Yes you will be OK to return to the UK
Remember as well that if the current passport has an extension on it from a previous early renewal that the extension period is excluded from the validity calculation.
This is the current UK guidance.
https://www.gov.uk/visit-europe-1-january-2021
There is a passport validity checker here for travel after 31st December here
https://www.gov.uk/check-a-passport-...1-january-2021