Something I've been considering:
Perhaps, the first wave in September/October was actually #COVID19 , but the rise we are experiencing now is in fact a misidentified wave of Influenza.
Maybe it sounds a little crazy, but it seems less so when we look at the details.

1 - Covid19 and Influenza have different optimal temperature ranges for transmission, with Influenza transmitting efficiently down to 5C.

Covid: 13-24C
Influenza: 5-30C
https://www.medrxiv.org/content/10.1101/2020.02.13.20022715v1
https://jvi.asm.org/content/88/14/7692

2 - Covid19 was in Europe in 2019, but didn't take off till March 2020. Why? Because conditions in Europe in November/December when it arrived weren't conducive to transmission - as they are not now in December 2020. https://www.bbc.com/news/world-europe-52526554

3 - Recorded Influenza cases have all but disappeared this year. Why? Likely, because people sick with Influenza are being recorded as Covid cases as they are testing positive.
http://www.ecdc.europa.eu/en/publications-data/influenza-virus-characterisation-summary-europe-november-2020

4 - So, when we look at all this together, does it not seem likely that the fall off in cases we saw in October was the end of the autumn Covid wave, and what we are seeing now in December is the rise in the winter Flu, misidentified as a 3rd Covid wave?

5 - Anybody exhibiting Flu-like symptoms is immediately recommended for a Covid test. How many of these will also get a Flu test? Very close to zero, I would imagine.

Efforts need to be made to figure out what's really going on here.