Car ownership is a steady drip of maintenance costs, and winter rubber is the one upgrade you can't afford to skip. If you wait until the first snowfall, tire shops get slammed, prices jump, and installation slots disappear for weeks. Early autumn is the soft window when manufacturers run rebates to move stock before the rush.
Haggling down the cost of installation and grabbing rebates should happen before you even think about how you're paying. Once you get the total price down, you can spread out the bill so it fits your monthly budget without paying extra for the delay.
A 0% intro APR isn't free money—it's a strict deadline. If you still carry a balance after 15 months, regular interest rates kick in on whatever amount is left, which instantly wipes out any deal you negotiated on the tires.