Unless you have a perfect door jam and minimal temperature fluctuations, most of the mechanical smart locks on the market today are a recipe for short battery life and lock jams that leave your property unsecured.

I can't drive a truck, weld, fix my truck, fly a plane, do real electrical, plumbing, concrete, tiling, etc. 

My plan is to repair the broken connection with JB weld and tighten up the screws, maybe re-coat with some silver paint.

Also, MANY items that people keep in a fridge can be left at room temperature.

I currently have 3 x 50 gallon tank heaters shared among 6 units - and I pay for water and electricity for the hot water heaters.I've recently been investigating tankless due to lower operating cost - but they have a higher upfront cost - and feedback from plumber is that cold winters (here in the midwest) can result in them struggling to keep up when the temperature drops below freezing. 

@Jeff Rollon -Just the weather alone, San Diego has the best temperatures in the entire country. 

No electric probably means no heat (blower or igniter) for both units.You may only have 90 or so more days until you start to get freezing temperatures.If your repair is going to be a while, you might want to consider weatherizing the water system by draining it.Also if you used LVT, read the materials that came with it.The one's I have seen have a temperature range to keep it at, and the ones I have seen out of that range have wrinkled to some extent.

Phone is only for emergencies which is generally temperature, fire or water related problems.

Request that the new tenant and existing tenants all take temperatures daily.

The peak of STR activity is the festival season, as you correctly noted, and the demand for STRs does a slow decline after that, as the transient population returns to their main residences around the country for summer, and as temperatures start to go up dramatically here in the desert.