When things go wrong, it really doe’s highlight the problems with the scheme right now and the lack of support you get past a certain point to remain mobile. Epecially with such long waits for some cars and the lack of options now over what there has been in the past and also the higher AP’s.
Not all models come with heated seats and it may add a longer wait, could you not consider an aftermarket heated seat cover that plugs into the 12v.
Someone did post recently they’d gotten a Skoda karoq in 3 months but was the 2.0 tsi which is the least efficient engine. Even then, what would you do in the meantime, get something off the scheme.
We used to have to fit 2 car seats and my son in the middle as was a squash. so we opted for a seven seater like the grand c4 Picasso and it had 3 independent seats in the back rather than a bench type seat and was great.
One of my kids passed away in 2017 so we no longer needed such a big car, so not really looked at those lately, but i do understand your needs regarding space for car seats, which is probally the no1 priority and then the others are secondary and only test driving them would you know if they good for you.
Its a horrible situation for you to be in and the fact that Mb will just leave you up the creek without a paddle in 28 days is another one of the reason I think they could do alot more to help people out and find them or offer an alternative to what they actually offer.