Heavy snow is causing travel problems for a second day, with schools shut, roads closed, and trains - including Eurostar services - cancelled.
The cross-Channel train operator said it had cancelled all services due to bad weather in France and Belgium.
Meanwhile, hundreds of schools across East and West Sussex, Kent and the Channel Islands are closed.
Eurostar, which runs trains between London, Paris and Brussels, has advised passengers not to go to their departure station for the remainder of the day.
Heavy snow in north-western Europe is causing severe travel disruption, including the cancellation of hundreds of flights via Frankfurt and Paris.
Frankfurt - Europe's third largest airport - earlier closed its runways while snow was cleared, and is now warning of possible delays to flights.
Paris's two main airports - Charles de Gaulle and Orly - are also operating at reduced capacity. Passengers are advised to check with their airline before travelling.
In other developments:
- Cross-Channel ferries are operating but passengers are advised to allow extra time to reach ports due to poor conditions on the A2 and A20 in Kent
- About 500 passengers on a ferry from Ireland to France spent the night anchored off Cherbourg in north-west France after the vessel failed to dock
- Many Sussex and Kent roads remain treacherous with a section of the M20 in Kent blocked and part of the A2 Dover Road closed. In Sussex, a section of the A22 is closed and conditions are particularly bad on the A23 Brighton Road
- Gatwick Airport is warning people to allow extra time for their journeys due to the problems on the roads
- There are drifts up to 6ft (1.8m) deep in the western part of Jersey, and the police have yet to reach some areas
- Two people were trapped under a tree which fell during blizzards in the island
- It is feared the cold spell will have an impact on the main outdoor crop of Jersey Royal potatoes, which are planted from January onwards.
- The Cheltenham festival will go ahead despite overnight frost, but the first race has been delayed by 35 minutes
- Train services in southern England are being affected, with Southern, Southeastern and First Capital Connect services reporting delays and cancellations
Overnight hundreds of drivers were trapped in their cars in Kent and Sussex.
Sussex Police said they dealt with more than 200 collisions across the county in 24 hours, with drivers spending the night on the M23 in Sussex and A2 in Kent, in temperatures as low as -3C.
Sussex Police said the force had been "stretched to capacity" overnight but the focus was now recovering abandoned vehicles.
Ch Insp Phil Nicholas, from the Road Policing Unit, said: "Many people fell asleep in their cars or abandoned them so even when the roads did become clearer they were still blocked by many vehicles.
"Although the conditions have improved slightly, we are asking people to not make any journeys unless they are essential."
Drivers spoke of taking several hours to complete short journeys, while a party of 120 German students had to be put up in Hastings town hall in East Sussex for the night when families due to look after them were unable to reach them.
Gatwick Airport worker Jonathan Lara was stuck on the M23 after taking eight hours to travel fewer than eight miles.
Speaking to the BBC at about 01:30 GMT on Tuesday, he said: "It looks like the gritters have been totally caught out by this.
"I've been stuck in the same place for about three-and-half hours now and it looks like I'm going to be here for hours yet."
The Met Office has issued yellow warnings, which means be aware, for snow in parts of Scotland, the east, south-east and south-west of England.
BBC weather forecaster Holly Green said the worst was now over, but further snow and sleet showers were forecast for Tuesday, with 2-5cm possible in north-east England and north-east Scotland.
Temperatures will reach between 2C and 4C, but feel like -4C to -5C in the south-east of England.