If I trusted the dealer some, I'd at least talk to them and see what they were thinking of doing to make it good--give them a chance to make things right. If I didn't trust the dealer, I don't know why I'd be bringing my RV there in the first place. That's possibly just me; it may not be the soundest advice in general.
Realistically, if you're upside-down in your financing, you may well just be out of luck. The same would be true in most cases no matter where the accident happened. Similarly, if you should have the misfortune of totaling someone else's camper or other vehicle, you (via your insurance company) are only on the hook for the value of the vehicle, not for however little or much they may owe on it.
If the dealer is in New Hampshire, the laws might be a little different than in Vermont, but a local attorney and/or your insurance agent ought to know those details.
