So expect it to have about an average lifetime of a non-electric vehicle. You will probably have very little issues for the first decade outside of regular maintenance based off of mileage (brakes, suspension, tyres) and less to worry about related to the engine. Battery life will slowly degrade as it would in anything, but you can assume that it might lose between 1-2% of battery life per year depending on your climate. Extreme cold and heat are bad for any battery regardless of chemical composition. If you expect to have your car for at least a decade, you'll see a decrease in max range but nothing overly significant. All that being said, we haven't had electric vehicles on the road long enough to know exactly how they will age in all conditions, and they are only getting better, so even my estimates might be overly pessimistic.
For reference, I have been looking at electric cars a lot as my current vehicle is over 15 years old and it's getting to the age where some expensive repairs are probably needed soon.