Welcome! housing two snakes together can be done but is very difficult and certainly NOT recommended with out TONS of knowage.

Tubs are fine but with cool room temps difficult to set up. The hot side isn't a problem but regulating the cool side is. I can't tell you how to do things but I can offer some Ideas.

a. You could place the tubs in a room and add supliment heat to the room to keep the ambient temps at 80º

B. if you can run cool side heaters to regulate the cool side temps they MUST be controlled with a T-stat.

C build an insulated box to hold the tubs that will help hold the escaping heat of the hot side and raise the ambient temps, and or add a ambient secondary heat source to the box.

D. Build custom enclosures (or a duplex enclosure, a really large enclosure that is divided with a single hot spot heater and cool spot heater spread across the divide) that are better at holding ambient temps and or use custom enclosures with primary (hot spot) and secondary (cool spot) heaters.

Some ideas, lots to think on. The correct answer is individual. My house is hard to heat so I use secondary heaters on everything but that is me. You might have a small space that can easily be used to house snakes that stays warm due to its location (beside a hot water heater or something)

REMEMBER, do not guess temps thermometers are needed, heaters get hot they need controls, and there are very few absolute answers just lots of opinions and this works for me.. options. It often take some common sense and tinkering to get things tuned.