Hi whatnow
I think I'm right when I say your home insurance policy is separate to your car insurance policy. They may well be underwritten by the same company but they are entirely different insurance policies covering entirely different things.
You don't say why your home insurance has been cancelled. It may be for example, that you've not paid the premium/instalments and if this is also the case with your car insurance, then they may well do the same. However, if you're uptodate with your premiums on your car insurance, you have nothing to worry about.
There may be a problem when you come to re-insuring your car at renewal date because one of the questions you are usually asked if whether you have had insurance cancelled or refused - to which you will now have to reply "yes."
Correct me if I'm wrong guys but this is the way I see it.