My DM lives alone. We've only see her outside since March. Although legally she can bubble with us, we've been cautious as we are a risk to her.
I've just had a chat with her and she's almost certain that she won't be visiting us at Xmas. From the start I said the decision was hers, based on how she perceived the risk, and that the DCs and I cannot isolate on the run-up to Xmas. Her decision was made based on a report on a radio show by a doctor about staying 2m apart indoors, no board games, using your own cutlery etc. She thinks she'll just spend the whole time with us worrying, so it's not worth it. I completely respect her choice.
Those of you that are joining together this Xmas, what are you doing to ensure you all stay safe? The fact that we can join with two other households doesn't mean that the risk has reduced. Will you be SD indoors? Keeping all the windows open? My DM may well change her mind when the reality of spending all of Xmas alone sinks in, so I'd appreciate some suggestions of how others plan to deal with it.