Hello @John_O 

I wish I could do some help. 

1. before installing camera outside, please check if the Garage/ Door /outside area has a strong Wi-Fi signal (at least 2-3 Wi-Fi bars), otherwise you will need to relocate router or get an extender/ AP to boost signal or Ethernet. 
2. Outdoor camera like Tapo C310 has no problem being used inside the house. 
Put camera close to router, set it up in Tapo APP, then position the camera outside. 

Thanks,  @Solla-topee 

I was planning to check the WiFi signal over the garage door but only by standing on something and waving my phone around (and,  maybe,  powering it off and back on). I don't know how to check for the number of bars though. 

With my C200, the instructions were to set it up in close proximity to the router. I did this and was able to then disconnect it from the mains supply and reconnect it elsewhere. I read somewhere that the C310 doesn't have man internal battery that would allow this. It seems to me it can a bit of a leap of faith buying one of these cameras

Either way,  I'm planning on setting it up indoors initially. I just have to source a class 10 micro sd card first. 

Hello @John_O 

You may need a ladder to install outdoor camera to somewhere higher, and to check Wi-Fi signal strength there.

Tapo C310 does not have an internal battery, it use a power cord around 3-meter long. 

Thanks, @Solla-topee but that's not an option.  If I was to fix the camera above the garage,  it couldn't provide a view of the front door unless I stuck it on the end of a 45° flagpole. It's beginning to look like a potential non starter for me but I'll give it a chance and see how it fares when installed indoors.