It can vary greatly company to company... some large companies can be very inflexible as to official policy and exceptions.

Your best bet may be to try and negotiate some sort of per diem, say $150/night (including food?) where both of you can make out in the long run.

Do be wary of home ownership costs such as closing costs, taxes, insurance and upkeep, and what happens if the employment (or assignment/contract) falls through?