OK, thought we were talking about the 451. That higher powered charger on the 453 was a good move. I presume that in Europe with much more widely avalable 400V 3-phase power the 22kw charger that can charge in 45 minutes is still avaiable.
I live out in the country far from public charging infrastructure, so I carry a just-in-case generator on a cargo rack behind my ED. So far haven't needed it, thankfully, but I've only had the car for a few months now so we'll see what winter's like...
My aftermarket 16A L1/L2 EVSE works fine with the generator as-is, but the OEM Lear EVSE in the tailgate apparently checks for continuity between ground and neutral (common in properly wired houses) and refuses to operate without it, and this generator doesn't bind neutral to ground (called "floating neutral," common with generators), so I made a simple plug with neutral wired to ground. I plug it into the spare outlet on the generator and that fools the EVSE into thinking it's connected to a properly wired house.
According to my research, all EVSEs are suppsed to do this check, but many aftermarket ones don't bother (especially cheapie Chinese ones like I got).
So if your EVSE refuses to charge from a generator - as it should! - you can try making a "bonding plug" like mine, just be very careful you know which prong is neutral because if done wrong it could be very dangerous - imagine every metal surface that's supposed to be grounded instead has live AC voltage on it, and then someone touches it...
Good luck, and be safe!
PS - Hopefully I never need the generator, but some day I'd like to convert it to work with a wood gasifier so I can charge for free while boondocking or living off-grid. And renewably, to boot!