In the research process it was discovered that there is an error in rule 240 of the HighwayCode that doesn't list bus stop clearways as somewhere you must not stop.
Rule 240 of the HighwayCode lists a series of places where motorists must not wait or park, including motorway hard shoulders and cycle lanes, but it does not mention bus stops.
The best advice is in the HighwayCode - drive with care even if roads have been salted, be prepared for road conditions changing over short distances and take care when overtaking gritters.