The larvae form of this mosquito lives exclusively in old tires, and old tires are identical across all habitats. If water dries before larvae transition to adulthood, they die. Rain (which fills the tires with water) is more frequent in Florida than in Southern Maine. How do you expect mosquitoes to differ in respect to variation in size and age at metamorphosis?
Due to the lack of water, the number of viable individuals can sharply decrease. Adults in Southern Maine may be smaller than in Florida.