United has a ton of planes and crews sitting around doing nothing right now during the pandemic - they could literally create an instant hub somewhere if they wanted to (assuming they could get the gates). But where?
If anything, the pandemic has encouraged consumers to avoid hub connections whenever possible. In years past, United Airlines travelers headed from Boston to Tampa would be routed through EWR. Those departing Milwaukee would have to connect through ORD to reach Tampa. Pax using LGA would have to make a connection at IAD en route to TPA. Now, UA has decided to no longer force Tampa-bound passengers at BOS, CLE, LGA and MKE to endure connections at busy international hub airports. After all, even an hour or two at EWR, IAD and/or ORD could be a major concern for older "snowbird" travelers, elderly VFR pax, etc. It will be very interesting to see how United's new p2p services to Florida do. I certainly can't see United or its passengers wanting to make connections at TPA when headed to places like CUN, MIA, SJO, SJU, etc. though. Perhaps those destinations could see their own p2p services from the likes of BOS and CLE - rather than connections to a new TPA hub.
But they do lack good coverage in the southeastern US like Delta does from Atlanta (world's largest hub) and American does from Charlotte.
Southeastern markets that are absent from the UA route map - say, AGS (Augusta, Georgia) or MGM (Montgomery, Alabama) - obviously aren't possible from EWR/IAD/IAH/ORD. I just can't imagine those types of markets ever working from a TPA hub either. Then again, quite a few Southeastern markets that had been missing from the UA route map, like EYW, HHH and TLH, have been added in recent years. I think coverage of the region may have been pretty spotty by PMCO and PMUA, but the combined carrier seems to have done a pretty good job filling in as many holes as it can.
Additionally, Houston serves as a great United hub to Latin America for the central and western US, but is not geographically well-positioned for serving the eastern US the way American is with its hub in Miami. Is there somewhere United could establish a hub that does some combination of what Charlotte and Miami do for American?
CLT seems to be an extremely profitable hub for AA, but MIA seems to be middle of the pack in terms of AA hub profitability. There just isn't much that those hubs do that UA can't do through its EWR, IAD and IAH hubs though. I suppose a traveler from BHM to NAS or SAV to SJU probably won't find any appealing routings on UA - but I doubt there are that many travelers on routes like that. Folks in the South do not face the same harsh winter weather as those in the North do, and many that do travel to beaches opt to drive rather than fly.
Really the only thing UA is missing out on is the O&D between Florida and Latin America/the Caribbean - but its not like UA's international gateway at MIA (inherited from Pan Am in the early 90s, then quickly cut after the airline declared bankruptcy in the early 2000s) was a success. Plenty of other carriers, both domestic and foreign, continue to fight over that traffic. I can't see United wanting to jump back into that fray again, especially now that carriers like B6, NK and even WN have established themselves in that realm.
The really intriguing alternative that remains: Tampa. The Tampa Bay metro area has a population of 3.2 million, the 18th-largest metro in the country - larger than Denver, Charlotte, or Salt Lake City which all support substantial hubs. It's also one of the fastest-growing (nearby Lakeland as well), and has manageable low-fare competition. The housing is far more affordable than the Miami area. It's also about an hour from Walt Disney World, the largest tourist attraction in the country (soon to be connected by the Brightline train). And it's not just tourists - there are plenty of business travelers as well (United's core market). Tampa has been steadily growing its corporate presence - especially financial - and it's the center of Florida's High Tech Corridor.
Is TPA not already a "substantial hub" for WN? I should think quite a few WN pax connect through TPA en route to places like FLL, HAV and SJU. Perhaps in the future WN will offer additional connection opportunities given its longstanding strength in the Tampa market. NK, F9 and DL have also shown quite a bit of interest in the TPA market in recent years - adding p2p services long before UA did. I suppose if UA's p2p services catch on, the airline could attempt to forge closer ties with Silver Airways. Perhaps UA passengers will be willing to connect to 3M flights from TPA to popular destinations like EYW, FLL, NAS and PNS?
As you can see, it's much better geographically from the eastern US to the Caribbean and Latin America than Houston is. Would it cannibalize traffic from IAH? Based on American's service to the same region from DFW and Miami (the equivalent of United's IAH and Tampa), we don't think so. DFW has Latin service nearly as comprehensive as IAH despite American's Miami hub. The two hubs actually reinforce and support each other and give American a dominant position in Latin America. United could challenge that dominance with a combination of Houston, Tampa, and Newark/NYC.
Actually quite a few of AA's DFW-Latin America services have been cut lately. I think to reinforce and support the MIA hub during these challenging times AA has had to reduce and eliminate quite a few flights from DFW. Also, O&D from Tampa to Latin America is probably far weaker than that from South Florida or for that matter Orlando.
Florida is the third-largest state in the country at 22 million and growing fast. United needs a strong presence there to match its strength in other top five states like California (38m), Texas (28m), New York (20m), and Illinois (13m). A hub (or at least a strong focus city) in Tampa is the best strategic option for them to tap that market. This pandemic will reshuffle the airline pecking order - why play defense when they can seize the initiative and fill a long-standing and growing gap in their route network while also putting more planes and crews to work?
Florida was a very weak market for PMUA. CO brought a lot of Florida service to the combined carrier, and it seems as the merger progressed, more opportunities arose - new services to ECP, EYW, SRQ and TLH spring to mind. There was also quite a bit of "connecting the dots", including a resumption of service between South Florida and California, new routes between Denver and the Florida Panhandle (as well as Southwest Florida), vastly improved connectivity between IAD and Florida, etc. I can't help but wonder about additional opportunities for UA in Florida like APF (imagine how popular an E-jet between Naples and ORD could be!), a return to DAB, perhaps even a resumption of MLB. There's certainly no need for a TPA hub, though I imagine there is the possibility of additional p2p flights being added if the initial batch are successful. Stuff like BDL/BUF/CMH/DSM/GRR/MCI/OMA/PHL/PIT/STL-TPA springs to mind - if only at weekly, highly seasonal frequencies initially.