You will probably be fine as a Heathrow Terminal 4 hotel is at your point of entry, even if it is a distance away.
The guidance also says that you must:
- travel directly from your port of entry to another port of departure in England
This is indicates that travelling and using public transport is allowed.
Note though that Terminal 4 is currently closed as it is being used for Red List countries. Distances from the hotel to other terminals (you will most likely arrive at Terminal 2 or 3) are found on the hotels website:
Heathrow Terminals 2 & 3 – 4 miles
Heathrow Terminal 5 – 3.5 miles
Credit:stackoverflow.com‘