I texted her to see what the temp is today and have not herd back.

In Georgia we mainly have temps of 60 - 100 about 8 months of the year and then 4 cold months down to 20 degrees at the coldest.This is just an average of what we have here.

And we have seen a ton of single digit temps this year.I use landlord locks, each unit is keyed independently, yet I have a master key that works on all of them.I can change out the tumbler and rekey a house in 15 seconds per handle.

In Iowa we had more snow and colder temps since 1886.

They do not seem to have an easy scheduling feature (setting different temps at different times).

The high temps from self clean dry circuit boards.

Nothing like those 3:48 PM sunsets and 20 degree high temps in December. 

Thus the thermostat is reading the main floor temp and shutting off before the up stairs gets cool (if it could even do that to begin with).You have two options.

The caulking will expand/contract with changes in temp and humidity, and as building materials shift over time.(4) If you don't know the grout color, and it isn't a straightforward bright white, etc, tear-out and re-tile will give you the best overall finished product (and will likely allow you to determine the issues causing the cracking).As a general rule of thumb, it's best to purchase grout and tile caulking for all tile jobs (when starting from scratch).

If you want her out I'd suggest discussing with her ASAP to get the temp on this, then if there's any trouble consult an atty.