From BBC wales today:

Patients have been asked to stay away from A&E departments and hold off from calling an ambulance unless they have a life-threatening emergency. The Welsh Ambulance Service said Christmas and New Year is its busiest time, and asked people to know their limits while drinking alcohol on New Year’s Eve to avoid extra demand.

https://www.bbc.co.uk/news/uk-wales-50949501

This follows the recent case of a patient in Wales who died on a frozen pavement waiting for an ambulance:

Deadly NHS Wales Ambulance delays not a sign of pressure ‘across the UK’

There has been no comparable call from NHS Scotland or from the Scottish Ambulance Service.

From BBC Scotland in November 2019

The NHS in Scotland is to receive £10m to help cope with the “particular pressures” of winter, the health secretary has announced. Jeane Freeman said the money would go to health boards and the ambulance service to ensure they were “well prepared” for the coming months. It comes as Labour’s Richard Leonard accused Scottish ministers of “failing to plan for the future of the NHS”.

https://www.bbc.co.uk/news/uk-scotland-scotland-politics-50281603

What about England? Well I’m guessing people don’t need to be told to stay away as the awful waiting time performance is well-known. See:

As winter bites NHS Scotland A&E is still massive 13%* better even though NHS England fiddles the figures!

You are MORE THAN TWICE as likely to spend more than 12 hours waiting in A&E in NHS England than in NHS Scotland

One English Hospital, in Cornwall, has urged patients to stay away:

https://www.cornwalllive.com/news/cornwall-news/people-asked-stay-away-derriford-3687398

Cornwall has 10 MPs, all Conservatives.