If you are going to be moving a lot, you might consider a cartridge which is easy to get anywhere. .30-06 comes to mind immediately, especially if you reload. I use the Lyman 310 tool mostly, with a Lee hand press if needed for full length resizing. All of my reloading stuff fits neatly in an attache case I bought at the Goodwill, and that includes dies for .30-30, .308, .30-40 Krag and 7x57mm. You can reload the .30-06 with squib loads for small game up to 220 grain for big, mean and nasty critters.
Actually, .308 would work just as well although marginal for elk from what I have been told. Either of these would be fairly easy to find, no matter where you are. I would throw .30-30 into the mix also for the same reasons. I know that it is not an elk cartridge, but it has put down its share of elk none-the-less.
-Kees-