If he/she has been in the biz for long enough, they’ll not only have faced this situation, but seen a lot of different solutions to it (some that worked, some that didn’t). Talking with him/her and getting some options on paper, will help you figure out what will work and what won’t, before you spend any money. If your realtor thinks that’s dumb or blows off that concern, perhaps shop for a different realtor who understands how big a deal this is, and is willing to work WITH that reality, rather than AGAINST it. Remember, that realtor’s salary will be paid from your house’s proceeds, so you’re signing their paycheck. They work for you. If they’re working for you but not with you, find someone who will do both.
One additional option I thought of while writing this, was to rent a nearby house so that you could LIVE there, rather than camping all the time. If kiddos have a hard time with sudden change, visitors or whatever, the RV might not be much of an improvement. But a solid home with their specific bedroom assignments, might make the whole thing easier. And depending on your real estate market, it might be cheaper than buying an RV.