Where in Europe should I spend Christmas?

I have to be in Dusseldorf from 27 Dec-7 January so I have new years covered, but I’m looking for somewhere to spend Christmas. Since I won’t be visiting friends/family, I’d want somewhere that doesn’t shut down for the holiday (like most of England) so I can still get a good meal on Christmas eve/day. Somewhere with outdoor markets, entertainment, hot mulled wine, etc. Thinking maybe Prague, Innsbruck, somewhere in Ireland? I don’t know. Somewhere with a pretty old city center where I can sit and enjoy a drink and people watch in a pub while maybe meeting some locals kind of place.

Vienna? Fabulous Christmas markets.

Split, Croatia has exactly this. The whole square in seafront becomes a ”Christmas living room" with bunch of people enjoying delicious food and drinks, all in that Christmas decor and feeling. Also there is great music and overall great vibe.
Some photos: https://www.facebook.com/media/set/?set=a.271650279625528.1073741840.170975886359635&type=3

I live in Dublin and can attest to how completely dead Dublin is on Christmas day. It’s downright creepy!

I too will be hunting around for a place to hang out for the holidays, since I got super sick last year which kept me from taking a flight over to the German Christmas markets.