No offense but you should of looked before you aquired the camper... It will be expensive repair and probably not worth the price of the trailer.. If your handy you can do it yourself. But if you never done it before it will be a daunting task..
My old coachmen had a small spot with no wood in the corner ( 2003) and I just liquid roofed it and put eternabond tape over that part with no wood..
I got rid of that trailer as there was mold in the walls from that leak and it was a health hazard.. I disclosed all this to the new owner...
It it dont leak dont worry about it...
How bad can it be that you dont think it will hold up snow?
Mike L ... N.J.
2006 Silverado ext cab long bed. 3:42 rear. LM7 5.3 motor. 300 hp 350 ft lbs torgue @ 4000 rpms
2018 coachmen Catalina sbx 261bh