As far as I know, there are no restrictions any more.

If restriction exist, this will be country specific. Best check on a website for travel advice of foreign affairs.

As a Brit I've travelled to all these countries except Portugal in the last seven months and not once been asked for proof of vaccination. I hope that offers some reassurance.

Of course, you can always check the latest FCO advice on entry requirements before setting off on your trip.

Worth having masks with you just in case there is an expectation. On German trains and buses I was asked to put one on. 

There aren't any mask requirements left on any trains in Europe. In other public transport only in Cyprus and in Greece (only city transport).

Thanks everyone, that’s great. I suddenly got a last minute panic that I hadn’t sorted this out! We leave a fortnight tomorrow for a six week trip and are very excited! This community has been a great help, so thanks for everyone taking the time to respond. It’s really appreciated.