racedo
They won't be happy because the loss of foreign income with be felt quite badly, plus the welfare costs of most of the UK travel industry being out of work will out weigh any benefit from a "staycation".
The UK is a trading nation, it needs its transport sector to be fully operational, and not just aviation.
Personally I think S21 will happen. S20 happened to an extent, and now we have safe and effective vaccines. Too many jobs and business are riding on it, both here and abroad for it not to happen.