We own a 1997 16' Scamp
. We bought it 4 years ago and there was floor damage caused by window leaks
at the rear storage areas under the seats of the dining area. There were no holes but dry rot that I probably could have put my fist through. The total affected area was 2-3 sq ft. I've been a sailor for decades and have spent a lot of time in boatyards. I learned a method for strengthening areas of dry-rot and used it on the Scamp. I purchased some plastic syringes from West Marine. Then determine a drill size that will accept the syringe ( they can be clipped to permit more flow). Take some tape and mark the drill bit for about 1/2". Drill a lot of holes about 2" apart. Mix epoxy with acetone until it is much like water. It doesn't take a lot of acetone to get that consistency, so start slow. Use the syringe and inject the thinned epoxy into the holes. Wait an hour and repeat 2 or 3 times. It takes over a day for the thinned epoxy to cure. When finished, apply some fiberglass mat and paint
with un-thinned epoxy.
Sometimes the dry-rot is bad enough that the thinned epoxy will run straight through. Paint the underside with un-thinned epoxy and allow to cure. When hard, put duct tape on to seal small holes. remove when finished.
I agree that a new floor done right is better than a repaired floor. It is also true that using a scamp is so much better than working on a job the size of replacing a floor. I repaired the floor 4 years ago, have used the trailer 8 weeks a year or more and have traveled from Mich to the west coast, Texas, Florida and spend about 2 weeks a year using it in Mich. The repair is as good today as when I first did it. I did put up a metal carport to keep it dry when at home which has to be a help.
I have no idea how bad your damage is but thinned epoxy MIGHT be an alternative that would use less of your camping time.