As for COVID19, your trip is not impossible, but unlikely.
In any event, should you be able to travel to the UK, I highly recommend that you reduce the scope of your travels.
In 2017, we did South Wales and England in 28 days. Originally, we planned to go to Scotland as well. We have been to the UK several times and love it immensely, but there is always more to see.
We rented a car the entire trip and stayed away from major cities. Cardiff and York were are largest cities. We stayed at either B&Bs or small hotel near city or town center and booked places that had parking for our vehicle. Parking is a huge issue in these historical cites and towns with narrow streets and little parking.
If you plan to visit London, Edinburgh, etc. don't rent a car for that.
Here is my 28 day review with details on our trip including lodging, tours and travel. If driving, make sure you get a nav system on the vehicle.
28 days in Britain and Celebrity Eclipse home