I'm betting nothing. I don't think Montana advertises for use as Full Time (not that it's a problem), so they are unlikely to consider obliged to accommodate her non-recommended use.
Standard fare for warranty work is, the dealer gets around to it when they get around to it. Paying customers come first and they fill in warranty work when they are slow. I've never seen a warranty that had a time requirement. It's not uncommon for buyers to lose much of their first summer with an RV waiting for warranty work.
Unfortunately, if they have to take it back to the factory (unlikely), she's looking at some sort of medium term rental. Check airbnb for monthly stays.
