Temp does affect the hardener a bit. My working times here were generally less than 20 mins and I was a bit light on the hardener. If I was any heavier I'd get less than 10 mins. My garage was 100deg much of the time. But you get your strips ready, and in place, then mix then douse them. Do batches/layers. You're not gonna do a project at once, so don't try.
You mentioned bondo, I thought you were making 'milkshake'. A lot of times for enclosures, people will mix some bondo, resin and hardner to make a milkshake - comes out like chocolate milkshake consistency. Can dump that in and let it flow into corners to help seal any edges. Good for sealing, bad for structure.
You've got two sheets of wood in your door, which isn't really taking advantage of fiberglass. The best part of it is the ability to conform to shapes you cant get outta wood. With your front/rear out of mdf there, you may be better off just kerfing a piece for the edge there and gluing.
The kerfed corner thing doesn't really work there. It's a multi angle thing not as cutting and dry as it looks.
I left it this way because
1. It's less fiberglassing
2. I prefer wood over fiberglass for bass. Fiberglass isn't stiff enough unless your LAYERing it.
3. This actually gives me almost exactly what I need for air space, puts the speakers in the right locations. (These are actually semi tuned sealed enclosures, not normal 6.5 pods.)
The front and back measured out at an even 4" apart, will get me within the range I want, but on the high end. These are 2.25 at top, and 5 at the bottom. So close enough.
The ends will be as much wood as I can do easy enough, and any left over opening will get glassed.
The front edge actually has a bunch of angles and twists going on.
The bottom is angled up, plus has that rounded corner, and the face plate actually sticks out over the B pillar some when the door's closed.
That end will be all glass. With stiffening bars.
I'll see what I can get for pics tomorrow