Thanks guys, I was pretty sure there wasn't a way to do that. I'd almost split my current ball's tank for temp instead, but she JUST got to where she's happy and doing well. I am NOT messing with the established ball to rescue others.

I have extra totes lying around, and being the kiddo's are so small may do as yall suggest and use two small totes (shoebox size?) and split the heat.

Here is the next question, my UTH is currently attached to tin foil and duct taped to the bottom of the extra 20g tank. I was thinking to take this off and use that to split heat, but I am really worried that with the size of the bins they'll be in, that's too much heat. I do have a human heating pad but I am really super worried about the fire hazard of this idea, and lasting a couple months on hot hands will be expensive in the long run. Any more ideas are welcome.

Again, this could all be for naught, but I want to be prepared in case I walk in and fall in love.