I think my next step will be to try just the ERP8266 for the sensor. It will use less power with only one module. Although I may try one last debug of the digispark to find out what went wrong...

I think I'll start with the frankenstein firmware ; I didnt have much time tonight so I just knocked up a module for the DHT-11 but I'll have to test it later this week or on the weekend.

The firmware build was really quite straightfoward and quite fast which is good.