Jet2 have had a remarkable rise despite the profit warnings this year. I think they will probably continue at the same level for many years. But long haul would be a step too far. Like previously stated, they're doing what an other airlines are not doing and that's making money.
But long haul would be a huge risk. If and when they lower there fleet age they'll be in a strong position - then they could look at strengthening it and looking at other market propositions like long haul. I would expect the next few years to be interesting with some of the 757s and 737s coming to the end of the road.. Some which are owned solely by LS.