I'd be $12,000 ahead on this. You said that the hail damage was not terribly noticeable and that the roof appeared good. So, how much would it cost you to take it to a dealer/service place and have them check it out just to be sure. You could certainly consider investing about $300 or so in an Adco cover for the time you're not using it and definitely during the winter...pretty cheap roof insurance. I have no idea what the cost would be to replace the roof, but could it have some repair done to get you through the time you plan to keep it? It may be that there is not a thing wrong with it. My thought is that insurance was looking at having to replace the entire side that's pock marked and that would be pricey. All windows ok?
I'd hazard a guess that most of us are driving vehicles around with parking lot dings and maybe a few other bumps and bruises and don't feel like we have to dump the vehicle for that reason. If the damage doesn't stick out like a sore thumb, suggest you go for the $12,000 and be happy in the trailer you said you like.