Automated RODI/Salt mixing station with 2 50 gal reservoirs in uninsulated garage?

Thinking about setting up a new tank after 5y break from the hobby. I have a place picked out in the downstairs dining room. It would go against the wall that is shared with the garage.

I am contemplating building automated water mixing and changing station in the garage, with two 50 gallon reservoirs for rodi/salt water. I would use controller to setup small automated water changes throughout the day. ATO in the sump would also replenish from RODI reservoir as needed. I'd mix new salt water every 1..2 weeks.

Garage is not insulated, so with NC weather temps there can swing from probably low 40s to high 90s.

Do you think it's a bad idea? Or should be fine with heaters in the reservoirs?

Thank you.