Lancashire to Cornwall

McRiches

We will be travelling from Lancashire to Cornwall at the beginning of June and was wondering whether anyone has any tips for the route I.e what time to give the journey ( obviously google maps gives an est based on just a car, not a 1920kg + van being towed; where to stop for short breaks etc? Also for such a long route which day and time of day do experienced caravanners often get on the road? given that we hit Manchester, Birmingham and Bristol traffic, we were thinking of setting off on a Saturday or Sunday, roughly 6am??