There are two problems with this approach. First, the revenue to the company can't just be things like a paycheque your employer paid to you, a person. That income is taxable to you personally and your employer will issue you a T4 for it. So you would need to ask your employer to stop hiring you as a person and instead pay a corporation for your services. They might gleefully agree, because T4 employees cost companies a lot more than invoiced consultants. You would no longer be paid for sick days, statutory holidays and so on, and you would no longer get company benefits like private health coverage. Your corporation would need to spend some of your revenue on providing those. This is a non-trivial amount of money: when you factor in unpaid time between gigs, most invoice-consultants need to charge double per hour to make the same net as T4 employees with good benefits. You also won't be able to put any of your revenue into CPP or RRSPs unless your corporation pays you a taxable T4 salary. You'll need to do all your retirement saving yourself without tax incentives.
The second problem is the expenses. You can't just declare that your house and groceries are business expenses you can deduct from revenue. There are some day-to-day costs that a company can deduct and people can't, but there are rules about it. For example, our company provided us for a long time with a company car. We had to take a taxable benefit into our personal taxable income just for the car sitting there and being available to us. We had to track personal miles vs business miles (driving to the airport to go to a conference was business; driving to the grocery store was personal.) Yes, the company paid for the gas and maintenance and such, but as our car usage has dwindled we found it made sense to stop having the company car, mostly because of that standby benefit. The company can pay for your house and let you live in it, but you'll have a taxable benefit. Decades ago my husband worked at a place with a subsidized cafeteria: they had to take a taxable benefit for their $1 lunches. If you want your company to own your house and make the mortgage payment, when you sell it you won't get the primary residence capital gains exemption; your company will pay tax on the entire profit, less whatever maintenance expenses it tracked over the years.
So I'm not saying it can't be done. I am saying it's a lot of paperwork and book keeping and people whose entire job is to reduce the taxes their clients pay have tried it, and other people whose entire job is to make sure the government gets the tax revenue it's counting on have put rules in to make sure they still get their taxes. If you genuinely had a business with revenue other than two people's paycheques, you might find that business pays less tax on that revenue than you do as people. And then you might find that by the time you get the money into your own pocket, you pay just as much tax in the end, just through a more complicated process. You have to learn that process to run a business; there's no benefit to learning all that if you're employed.
