You are buying this bike to haul groceries, kids, and gear instead of driving, so you want a frame and motor that last for years rather than a cheap build you will replace next season. Look for clearance discounts as summer ends, because bike shops slash prices on current inventory right before newer models drop.
When the release cycle shifts, last year's model is usually the better buy with identical frame geometry and a lower price tag. You just need a clear plan to cover the roughly $2200 typical US cost without draining your savings.
Remember that the intro window is a hard deadline rather than free money, and any remaining balance after 18 months will trigger standard interest charges on the full original amount.