you don't need that much space.
Well depends on how many printers you have.

i've got three on one desk and a 4th on the fridge.
there are pics around somewhere.
As far as temperatures go.

you're in california - don't think you'll need a heater - dehumidifier maybe.

My workshop (garage) varies between 12c in winter up to 30c on a hot summer day. They all Print fine, regardless of the temperature.
The humidity - far more important, hovers around 45-55% which seems to work well for pla.

The ends of the rolls do get a little brittle if nothing's been p[rinted for a while. I guess I should unload when i go away.
But as my annual holiday currently consists of 1 week at the beginning of march to go to the international slinging meeting in mallorca, hardly seems worth it :-)