This is getting stressful. I am all set up for winter adventures but there is no snow!
I am now used to the strange turning behavior caused by the flat profiled rear tire. Next winter I will try Heidenau K66 and K73 tires, they seem to be M+S tires in correct size for my bike. Just add spikes… Thank you, shyhander, for the advice.
I found a winter riding thread on a domestic bike forum. There is so much to learn and prepare. What type of spikes for which type of riding, heated visor, winter grade engine and lubrication oils etc.
My first attempt against the visor fogging up in the cold will be a motocross helmet with separate goggles, but it is good to know that there are heated visors available and they seem to solve that problem.