I think the two previous posts give you some good advice.
When you say you need to be within 1-1/2 airport, I'm a little confused. You do know Twin Falls has an airport, but with only 1-2 airlines. And, I'm not sure if you can drive to Boise's Gowan Field in that time, given the traffice.
Idaho Falls Regional Airport currently has service from 5 carriers and with a good chance of more on the horizon, or more direct flights to other major hubs. Two additional flights, from established airlines, were added with no big announcements this past summer simply due to demand. Plus, Horizon added their much larger planes with a different route to Seattle.
Ironically, just released in the news was that the Idaho Falls Regional Airport had the largest month in history for boardings.
Also, it may depend on where you need to fly, what would be best for you.
I think your needs for an airport may be greater than the flexibility for apartments right now, given the apartment information offered earlier. I'd encourage you to check out the two major airports for Idaho: Boise and Idaho Falls. And, then check out Twin Falls and even Pocatello who currently has one airline still providing service.