Maybe home depot/lowe's would be better.
Your ISO tote doesnt need to be superhuge. Just make it really cluttered so the crabs have a bunch of places to scramble in and out of, especially around the edges. I would try something crazy like lining the whole bottom with styrofoam cups, and sticking a crab in each cup. That'll slow crabbies down from reaching each other. Then put your decorations all over the top so theres stuff to climb and explore. Your pools or food dont need to go in the tote.
If the tote isn't too big you can put it over or against an air duct, assuming your heat is running. An electric blanket can help you bring more heat, but being at 72-75 for a little while should be ok. Wet a towel real warm and lay it over the tote before you cover it lightly with the lid.
You can use lamps for your 10g and KK, or just stick them inside the tote before you start loading it up.
Don't rush to start. Hopefully Godzilla will finish molting and start ambling about. That will prob be the best time to start.
Megmaholm is a godsend

A local fellow crabber. Lucky!
Things you can do ahead:
Get pvc couplings. They are $0.28 each and already uniform in size. Drill a hole near 1 edge. Make sure you have a bunch of them. Like your footprint (L x W) divided by 5, should do it. If they dont have enough i recommend subbing with pvc pipes that is the same in diameter as the couplings are in height, but ask the people, in case there's more stock in hiding. Rinse them after you drill them, there will be fluffy plastic crap all over. These couplings will most likely help you prevent a repeat, because the egg crate can't be pushed down against it.
I had more on my mind but now it's gone blank
Crabbers unite!!!