If at all possible patch it with metal- it will eliminate any chance of the fiberglass cracking and letting in moisture and rusting.
When you go to do your carpet lay out the carpet in the sun as you get ready. Just like a headliner it gets rid of the wrinkles from being rolled up for so long. Clean the floor as good as you can so the glue adheres well. I always draw a light chalk mark at the center on the front and back of the carpet, and start with the tunnel and work my way out.
68 Camaro 355/TH400/3.73- long term project
69 Nova 355/TH350/4.88- bottle fed Pete's Nova Page
69 Firebird 400 ragtop- all original