Roof Repair

We have a 2003 Four Winds Camper with a 3ft x 3ft "soft spot, where it looks like the wood underneath has rotted away, which make an big indentation in the roofing material. At this point I am afraid that a tree branch will fall on it and punch the roof. Uncovered water builds up in the indentation from rain. Right now I have it covered with a piece of wood and a tarp. Asked for some estimates on fixing and get from $5,000-$8,000 to redo the whole roof, on-site since it is on a Camp ground lot, and does not move, it is attached to a Florida room.

My question is, that if needed, could I get a piece of metal, and glue or eternabond it down to the roof to cover the spot and protect it. and then seal around it, for a quick fix.

Any suggestions

Thanks

Barry