Some of my wine is in a passive cellar... recently I opened a couple Barolo that were purchased on release and left alone for 20 years. Both wines were in spectacular form and did not show heat fatigue. That said, the cellar stays 12-18C and never goes over 18C. Once you get to room temperature, range, anywhere near 20C or above, I'd be really concerned.
Fluctuations are fine by can't be too extreme, as that will cause cork movement and/or seepage.
Coming back to the original post, my word how technology has advanced in a decade. If tenants or security is still a particular concern, you can mount a remote camera (e.g. Wyze) to trigger on motion and capture everything. They're so cheap now and the image/video capture is great. All you'd needs is a wall socket to plug into and WiFi.