I've done this many times although never with checked bags, it is possible to do in 1h 55m, although personally I like to leave a layover of 3h in order to be extra safe. WOW open check in two hours before departure at LGW
which is handled in the BA
area right in front of the main escalators up from the N/S shuttle train, but you might not have the best choice of seats by the time you arrive. I'd allow a good 45 mins for reclaim at the South Terminal and then the walk and train ride across to the North, which gives you 40 minutes leeway in case of delays to reach check in before it closes, 30 minutes before departure.
Is it the last flight of the day you'll be taking with WOW? If not, you might wish to consider the 'missed departure fee' option, where by if you miss your flight you give them a ring and they'll get you on the next open flight for a £50 per head fee. It might even be cheaper in that case to book on the later flight anyway, then if you do realise that you'll be arriving on time phone them up and ask to pay the 'earlier flight departure fee', which is just £15. You'll need to check with the airline if this has to be done 2 hours prior to you scheduled departure though.
...love is just a camouflage for what resembles rage again...