20 plus thousand a day coming in to country. Not one has been put into an hotel to isolate as yet.
Heathrow is reported to have 25,000 a day, about 10% of normal traffic. They normally account for a 1/4 of passengers, so you could make a rough guesstimate that there are in total 100,000 people flying into the country each day.
Plus the ports.
There are around 1m hotel bedrooms in the UK, so we'd be unable to quarantine every arrival for two weeks unless there was some cap on numbers.
Australia are rationing their arrivals to IIRC something like 5000 a week to ensure they have capacity & control to quarantine everyone. There are around 40k Australians overseas & unable to get home as the quota is full.
We'd have to limit it to c.70k a day, about 7% of normal flight passengers, to ensure there were enough beds & have a massive logistics operation to ensure people were assigned to vacant beds in hotels, transported to them, fed & monitored before being turned loose 14 days later.
The papers would be full of stories of people flying into Newcastle & that live in Cramlington being shipped to Cornwall to quarantine & being given a pot noodle beween a family of 4 to last a day, plus the stories of other families trapped abroad desperate to return home. The airlines would be moaning even more than now.
Far better to make noises about doing something while kicking the can down the road & waiting for warmer weather & vaccinations to reduce transmission.