I took my trailer to Duvall's and Danny looked at it. We discussed best way to repair it. In the end, he cut out the front across the trailer, added in a piece of marine plywood that was wrapped in the stuff under slide outs on travel trailers, then added an additional piece of plywood on top of that with flashing and silicone. Cost - $400 cash. Ugh....not a happy camper...but I feel this was my fault. I left the windows open most of the time thinking that because it was sealed it was ok. I am not batting a .1000!
Anyway - trailer is now repaired and I closed those windows TIGHT.