As alluded to above, UK quarantine will be a farce.
Re-route your flight via Dublin or any Ireland or Northern Ireland port/airport and you're exempt from quarantine - for long haul flights ADP/taxes tend to be cheaper via DUB anyway!
Or, save the hassle, land direct in UK, whether you give a mickey mouse address or a real one, as nothing appears to stop anyone flying out again 24 hours later.