Severe heat or cold wrecks havoc on battery life. Even in southern Canada I am certain you won't get anywhere near the 8 full years, now imaging you live anywhere that gets down to -30C frequently during the winter.
That's my biggest concern right now, heating an electric car uses the battery as heat is NOT a byproduct of an electric engine. Very impractical in the winter.
A 2016 NZ estimate of a second hand Nissan Leaf (compared against a second hand Nissan Pulsar), the battery replacement costs about as much as the savings in electricity costs i.e. the Leaf is quite possibly no better for the environment overall? Scroll to bottom of https://genless.govt.nz/assets/Everyone-Resources/ev-battery... - although it strongly depends on whether replacement battery prices dropped or how electricity prices moved.
And eventually battery replacement. “every Tesla vehicle’s battery is covered by an eight-year warranty”, and “For all variants the Model S and Model X, [the warranty covers] 150,000 miles, while the Model 3 Standard Range has it covered for 100,000. In the case of the Long Range and Performance versions of the Model 3, [the warranty is] 120,000 miles”.
I guess we don’t know yet how long the median battery will last but probably longer than the warranty, depending on how it is charged and other context. Battery replacement costs are currently very expensive, but perhaps will drop. Certainly battery replacement cost can’t be ignored, unless the vehicle is just scrapped because the battery replacement costs too much.