Some of Germany is allowing Christmas mixing. Definitely not every region.
It's up to 10 people from 2 households in most of the country. But I leave in a city where it'll be max 5 people from 2 households, excluding under 14s. Only between 24-26th Dec.
Those areas with a 200+ incidence (what the UK would call low and place in Tier 1/2) will have even stronger measures. My city has one the highest incidence rates in the whole of Germany and we've never gone over 220, yet we have the strongest measures nationally, and have been on the 'double red' alarm system for months.
We've been in partial lockdown (everything closed apart from schools and some retail) for 6 weeks now. We're going into hard lockdown on Wednesday, which will be similar to the one in March. Absolutely everything will be closed, apart from emergency childcare and essential shops. For 4 weeks.
It's crap. Some regions have already announced all non-essential activities (restaurants, concert halls, museums) will stay closed until 28th February 2021.
But it's even more stupid that in UK Tier 3 areas you can't meet a friend for a coffee, but in a couple of weeks you'll be able to see your extended family and ignore all social distancing, because it's Christmas and we all know how the virus stops working during that week, hey. Just so Boris can say he's saved Christmas...