As far as rehabbing, remember that when you watch HGTV shows, half of it is faked, the other half is untrue, and none of it shows the true time schedule (if you order and prefabricate materials for two weeks, but do the install on camera in a day, did the project take 2 weeks, or 1 day?). 

Not many work from home, so if internet happened to go out periodically.. it wouldn't be the end of the world; but I'd still like to have reliable connection - I have cameras and wifi thermostats. 

Make sure they agree in writing to the house rules and you have to monitor their stay, install exterior cameras and inform the guests that the property has security surveillance. 

I would get a sewer camera company to run their camera down the line and check the condition.

If so, any recommendations for a good camera that doesn't need to be hooked up to wifi?

They know they are supposed to get cameras approved.  

Works well with mobile devices and 360 cameras.

It it continues, consider installing cameras. 

We inspected the sewer from this point to the 41ft mark and was unable to push the camera further due to a separation in the pipe.

I could have prevented this by having the plumber run a camera down the lines.