Honestly at this point in time my advise would be not to worry about the temp. just let it cure longer. Though i cant say for sure because this only happened to my silicone and though i have a thing where my resin sits for two days they don't do the jelly thing.
We are in a spot of winter at the moment and we don't have heating in the house so the room where i do my casting is pretty cold (Big window, and no sun). My resin cures fine in the summer but i find lately that i need to leave them longer (they do cure in the pre-established time frame, they are just soft to the touch, as in i leave fingerprints on them if i take them out but they are pretty solid). so instead of a day it might be two that i just let them sit, after which i would take them out and leave them in the windowsill for some sun so they can cure better.
perhaps my dice is still fine because it hasn't been cold enough to bother the resin (conversion tells me that 40 Fahrenheit [i am assuming you are using american measurements] is fine enough for the resin - it being what we had here). but i think the very least you can do is try it out.
it is weird that two didn't finish curing while one did, but given what i know i figure it might be:
fixing bubbles and voids though, i actually got my first bubble the other day (didn't leave enough resin in the little pool of the spruce) and honestly, it should be done curing today, so i am going to try cutting the ugly bits, stick it back in the mold and try to fill up the space with resin. and that honestly is what i know on how to treat it if they are there. you can also get clear nail polish to do something similar for the smaller bubbles from what i read, haven't tried that though.
i cant help with stopping that before hand though. don't know enough about that.