So this has been running without any issues for two weeks. I have collected just over 10000 records, each with two temperature and one humidity value, plus timestamp and location.
Works just great. I can see exactly what's going on where, how cold it has been last night, if I should call the wife to open the garage door, how waterchanges affect temperatures in my tanks. I switched fans, reduced the lighting period, dropped an ice cube, disconnected the pond waterfall, etc, and all is clearly visible in various graphs.
I created a couple of those, some just showing the daily highs and lows, some humidity values, etc. Usually I just look at the temps for the two past days plus the current one.
Rarely ever something works out as nicely as this did. Only issue so far is that data is just collected and collected, after a year I will have over a quarter million records, and downloading that will take a while. By then perhaps the novelty has worn out and I'll download only weekly or so.