You sound like me about six months before I bought my EV
You're correct to weigh the advantages offuel savings against the risks of non-existent serviceability in your area (I did). I'm quite sure that I have the only Mercedes B250e within 1000 miles of where I live. There is also a zero chance of getting my local Mercedes dealership to service any of the electric bits in the car because they have neither the equipment or the training to do so.
So, if my battery, drivetrain, charging system, or related electrical bits break down; worst case means I'm towing it to Seattle. Not too big of a deal as I have other cars to drive, and can borrow a truck to tow it if the need arises.
I accepted that risk mostly because of the faith I have in my car's Tesla supplied battery & drivetrain, and because EV's have an overall track record of stellar reliability.
Like you, I'm also looking out 8 to 10 years with my car. I already know that there is a VERY small market for a car like mine in my area, but because I intend to keep it for a long time, resale value doesn't much matter because I will have already saved the price I paid for the car in not burning gasoline, and not having to pay for services like oil changes and related engine maintenance. With regenerative braking, I may never need to replace the brake pads either because they rarely get used.
Though your concerns are certainly valid, from my experience; I think you're reading too much into them. Notwithstanding the car's electric drive system, the rest of the car can be serviced at your local Fiat dealership. I really believe that a Fiat 500e will be far more reliable than it's Fiat 500 gasoline counterpart. Much more fun to drive too.
Hope this helps.