I will soon be transiting via London Heathrow with a 16 hour overnight layover. Since airside may be closed overnight (and my suitcase will not be checked through from my first flight), this will need to be a landside transit. I would ideally like to stay overnight at a hotel next to Heathrow (Premier Inn Terminal 4).
I have seen similar questions here about availability of accommodations and visa needs - this question is about staying compliant with current COVID travel regulations regarding self-isolation on arrival.
The UK government guidance on this (https://www.gov.uk/guidance/coronavirus-covid-19-safer-air-travel-guidance-for-passengers#transiting-through-england) states that passengers undergoing landside transit are exempt from the requirement to self-isolate on arrival.
However, the guidelines state that ‘You must remain within your port of entry until your departure from England’. The Premier Inn hotel is a 6 min walk from the airport terminal (https://www.premierinn.com/gb/en/hotels/england/greater-london/london/london-heathrow-airport-terminal-4.html). Would it count as leaving the port of entry (and therefore going beyond landside transit) if I stayed there overnight?