The Mercedes C300e looks as though it might be a viable alternative to the Tesla. 55 miles on the battery, a nice 2 litre Mercedes 4 cylinder turbo petrol engine. Not as quick, but back to Mercedes comfort....
That sounds like an optimum solution for your needs with all the local runs on battery I imagine and touring at leisure in a totally relaxed manner in comfort.
It's not as if any of us on here are really concerned about the running costs of petrol is it, more the availability of it medium to long term.