Packing tape:
Am I the only person who has had problems with the adhesive on (clear) packing tape?
I've had both:
a) adhesive residue needing to be cleaned with (several) solvents before continuing with the 'final' repair, and
b) adhesive interfering with the cure at the epoxy surface

Because of that, I'd only use packing tape (red vapor barrier/Tyvek tape is even stickier) as a 'field repair'.

About 5-minute epoxy in the tubes from the hardware store- I'd use it if necessary, but I've not found a type that cures hard - they all seem a bit rubbery (and not completely clear) in my experience. So I'd have to dig that back out at some point. Even the 'marine grade' 5-minute epoxies (like the System Three stuff in the small plastic bottles) seem too thick to wet out glass.
It looked like the OP's boat was back in the garage - doing the repair 'right' would only take an hour or so, and getting enough heat to the area should be possible, somehow.