Talk to Churchill about this, as if you cancel a policy before renewal, they will charge you a cancellation fee which can be up to £50 with some Insurers. In theory there is nothing stopping you cancelling and taking up a new policy online, with whatever offer is available,
If you cancel before the full year is up, you won't have a full years NCB for that year.
Work out what is best money wise, once you know the position.
Often it can be cheaper taking up a brand new policy each year, even with the same company, as the new business rates can be cheaper than those offered to a renewal customer. I have always found this practice to be a bit unethical, unless the Insurers were offering extra cover for their renewal customers as a loyalty bonus. But Insurers do it, because they can make more money from the inertia shown by some customers.