It is possible to freeze cauliflower cheese but unfortunately the sauce can sometimes turn thin and sligtly watery on defrosting, so we prefer not to freeze the dish if at all possible. You could reduce the amount of cheese slightly if you prefer, but you may need to add extra seasoning to the sauce.
Yes, you can freeze cauliflower cheese for up to 6 months. To freeze cauliflower cheese, allow it to cool, bag it up into a thick freezer bag, seal and then freeze.