Don't do it.
First off, ignore the bit about not having enough yeast to carb. There will still be plenty of yeast to carb your bottles.
Secondly, as noted, gelatin works best on beer that is already COLD. So if you do not have a way to get that whole bucket/carboy chilled down to 32° F, then don't bother with the gelatin. If you do, then read on.
Thirdly, after you've chilled the beer for a couple of days, add the gelatin solution (explained in other threads, but basically just add 1/2 tbsp gelatin to 200 mL cold tap water, leave it for 20 minutes, then heat it in the microwave to 150° F (but NO HIGHER) in 20-second bursts, then dump directly into the beer and (optional) stir gently). Wait 3 more days.
THEN rack the beer into your bottling bucket with the priming sugar solution, and bottle normally.