RE: Time v Distance
I think you are pushing the range at 85 miles. You will be OK in summer, unless you aim to drive assertively at full motorway speeds, it's raining, and/or you find your battery health deteriorating in a few years to come.
In winter, you will be on the ragged edge of its range, and it won't make it after a few years of range degradation, though what that actually is, and how quickly it happens, remains an unknown for the moment. You really want to start asking your employer where you can get a top-up of your battery. You won't need that much to get home, but you may find you need a few extra kWh to be 'safe'.
In regards getting held up on the motorway, this is the least of your issues. Your car works at its most efficient when it is driving slowly in traffic, whether stop/start or just slow. In fact, if you find you have range issues, you'll have to pretend like you are in slow traffic to get further!
What can be said is that if you can make the car work for you on that trip, and I am sure you can but you may well have to find yourself driving along with the trucks to do that, then you'll save a pile of money on fuel costs. The bigger your commute you can pratcially achieve, it follows the more you save.