Thanks for confirming Martin, that’s how I read the tyre rules too - only necessary in ice or snow, rather than set months. We got back Friday night (had a bloomin nightmare delay on Eurotunnel!), and had a great time. Visited the Porsche and Mercedes museums which were great and had an evening at the Stuttgart Christmas Market.

The journey there and back was great, French toll roads amazing and German autobahns good too albeit a lot busier. Now know that a sign with four diagonal black lines on a white background means no speed limit

Thank you to everyone for the advice!