Obviously the money is a lot better staying where I am, but with over 30 years 'theoretically' left flying should that be priority number 1!?!?
My point of view is that the world will most likely be a very different place 30 years from now, especially in terms of available fossil energy supplies (peak oil) and the effect on the transport sector and the impact on the world economy. Although I would not mind elaborating on this subject, this is not the right thread to do so.
In view of this, I would certainly not move to a long haul only carrier. As already mentioned, people will most likely shift from long haul to short haul vacations especially when fuel prices and taxes go up.
I have never done long haul, but feedback from friends who have done it would strongly suggest that it potentially shortens one's life span. Short haul on EZY for many years really isn't that bad, I've done it for almost nine now and the ACARS makes life much easier. Working out of a more northern base like MAN would give you the chance to do 'pretend' long haul flying to places like Sharm and Paphos. Sure, there's long 4 sector days, but we also get 2 & 3 sector days as well as SBY's. The fixed roster allows me to plan my life well ahead (I could work out if I am on a day off on the 24th of Dec 2020!) And the crew food really ain't that bad! One of my few complaints is the lack of staff travel on IATA airlines. That's certainly an advantage of working for airlines like BA or EK, especially considering the premium class privileges. If you could get your partner to work for BA, then you really have the full package!