We don't know enough about the rules of 2e yet to say how feasible an idea like that is. In theory, it should be pretty easy to just use the 2e stats for figures on an old 1e quest map. Kitbash some house rules for any terrain or traps or what-have-you that 2e doesn't cover and away you go.
Of course, doing this might alter the balance of play in some unexpected ways. For example, we don't know if the Overlord will still be spawning monsters in 2e (and if he is, it might work by different rules.) This would alter the number of new monsters coming in to the game, which might make things much too easy for the heroes (or too hard, if the printed monsters suddenly get harder to kill and there proves to be too many on the map for the heroes to handle.)
At the end of the day, even after the rules for 2e have been released there's a good possibility that changes to the rules will cause subtle but important balance changes if you try to run 2e rules on 1e quest maps. This isn't to say it's a bad idea mind you - I'm sure many will try it, and I may well be one of them - but we will need to feel it out as we go, once we have the rules to work with.
Short answer: I can't really answer your question. I don't think anyone except one of the FFG employees involved in development could at this point. Keep the idea in mind, though, and try it when you get a chance.