Ideas for December birthday party (age 6) under Covid restrictions

[Teppanyaki]

My son is turning 6 in December - I'm at a loss as to what to do for some kind of party. Assuming the weather will be not great so can't rely on doing a distanced 'play in the park'/woods with a couple of friends. There are 4 of us in the household so could really only invite one friend + parent (we haven't really done 'drop-offs' yet) round to play for a wee party tea.
I'd hope grandparents could visit separately.
Some indoor attractions may be opening but I'm not sure how confident we'll be about going.

In the summer kids were doing small garden "distanced" gatherings (although mainly just the parents distancing a bit).

We are in the south west and on the lower Covid risk scale but obviously could all change by then :(

Any ideas welcome even if no-one can guarantee they can go ahead!

It's my DD's 6th birthday in a couple of weeks. If the weather is nice she is having friends over to the garden and I've provisionally booked a bouncy castle.

If it's not nice (which will be than likely the case as we are on the wet and windy west coast of Scotland!) then we are having a zoom party. An hour of scavenger hunts/quizzes/musical statues etc then we will drop off their party bags afterwards (small town)

Thanks - hm, I'm on the fence re Zoom as not sure he gets much out of it, tends to run off having had an idea and then gets distracted, or just makes silly noises!

My dcs have had birthdays over the last few months and I’ve just kept it family. It just seemed easier.
They got gifts, cake, breakfast and dinner of choice. We went out for the afternoon.
It’s not the same but Dcs understood and still had a lovely day.

Does everyone in the family need or want to go? Since it is his birthday, wouldn’t it be better if two adults and four kids went and it will feel more like a party for him? Is there bowling in your area, with those gutter guard things?

Yes birthdays are definitely a family thing here (toddler sibling who gets excited too). I think if we did a day out as a family or even family + friend (which I'm now thinking might be a bad idea as DS would go on and on about who he's inviting without thinking that it'll leave his other friends feeling left out!) that'd be great, I'm just trying to think of somewhere good to go!
It's Bristol area. Bowling might be fun actually!