Neither of those dates works for me, I'm afraid.
In fact, I don't think I have any weekend date free in December now - thinking back to last year, we started looking at this in September to make sure everyone had it booked in - I fear that, whilst your intentions are excellent, it may be too late to organise anything with a good attendance.
Can I make the suggestion that we all do something in the New Year, as a belated Christmas meal? This will give us the opportunity to poll dates, let people recover from the financial arse-rape of Christmas plus give us all something to look forward to in the post-Christmas 'bliss' of Jan/Feb?
Gone but not forgotten:
325i M Sport (E92), Black Sapphire, Coral Red Dakota, 19" 225's, Seat Heating, 6FL and de-badge
Replaced by 6.2 litres of AMG powered C class.