Could EI extend the life of their ASL 757 (3/4 aircraft ?) contract to add PVD and SWF ? The market is proven and EI have connections to feed at Dub ...
I'd hazard a guess that the only market that's proven for those two destinations is people willing to fly TATL if the fares are very low or comparable to what Norwegian offered - something I'd be surprised if EI are able to profitably offer.
I'm also not sure if EI would want to start PVD given that BDL and BOS are 96 and 60 miles away respectively, especially considering the possibilities on offer with the A321LR/XLR's to go further into the US and Canada. Same with SWF given its distance and limited connectivity to NYC given the amount of flights already on offer from DUB to JFK and EWR (I accept there's more to the state of New York than NYC and it's a big state).
If I was EI, I'd be giving serious consideration to a seasonal TATL service from ORK providing the runway can handle an A321 going to NE USA, though I will admit I don't know the Irish market well enough to say for sure it could be a success.
Finally, an observation on my part is that another IAG airline (BA) set a precedent by scrapping LGW-FLL and LGW-OAK as soon as Norwegian moved their flights to MIA and SFO respectively. If it wasn't for Norwegian, I do not think BA would have started those flights to begin with.