With an improving economy, I would suggest that some of those destinations tried and withdrawn in the past might be worth another go - the likes of FRA, ZRH, BRU, DUS spring to mind. These should all be close enough for the 175's, or do-able in the Dash with only slightly longer sector times. I am assuming, of course, that suitable slots would be available and that the cost of accessing these airports makes services viable.
It's hard to see what else BEE are going to do at SOU with the 195's gone and no meaningful runway extension possible.