Yes they will ask for proof that your husband will be relocating to Canada especially if you run a business. Does your husband actually plan on relocating? Why would you send your children in October? August or the first week of September would be logical if they are starting school.
We are not planing on relocating in October precisely because of the childrens school. We applied 5 months ago and my application got through very quickly. We explained in our detailed plan when we made the application that we are planning to relocate next year by May in order to have time and look for children's school.
We dont run a business, we are both highly qualifies professionals with good jobs. We both plan on relocating to Canada.