Omicron has not really hit Cornwall yet. From 14th December, England’s total daily new cases have risen by 86%, Scotland’s 54%, Wales’ 48% and Northern Ireland 42%. Cornwall’s has dropped by 3%.
But all that will change in the next week as people come home for Christmas, second home owners take their winter break and students come home. Christmas 2020 resulted in a three fold increase in Cornwall’s cases. The Omicron variant is much more transmissible so this year will probably be worse.
The effect of incomers to a relatively isolated part of the country was covered in this post from August 2021.
Update 2nd January
New cases have doubled in Cornwall in the last 10 days, and are still rising. Omicron is here.