I mean, say you have 30 grocery stores, are you saying you shouldn't be able to build templates to deploy? You gonna have a guy drive all over the place updating schedules 24/7?
There's making a meeting out of something that should have been an email and then there's making a software project out of something that should have been an email.
The email is gonna go to the managers DL and it's gonna say "hey assholes the new temp is X set your shit to that" but in professional corporate speak and the managers will use their screwdrivers, take off one access panel and turn a dial ever so slightly" and I'll be able to see they've all done it right from my read-only monitoring system. And this has the side effect of keeping food from going bad in bulk because of a bug or fat finger or "Russian hackers" or whatever. The cost of the labor will almost certainly be cheaper than the cost of the software project amortized over its life.
To be honest, a grocery store is one of the most dynamic systems I can think of.
Edit: A bang-bang thermostat is not an appropriate solution for a grocery store.
Are the contents of the fridge also being adjusted via remote management tools?