I'd suggest public health authorities encourage outdoor gatherings, I mean public health missives (here where winter is barely an issue) never even make the distinction between indoor and outdoor, they just say "all gatherings bad", and for at least 6 months all gatherings with people you don't live with were illegal (but noone was listening, nor could they really enforce it). But there is a real difference in transmission between outdoor distanced gatherings and indoor close proximity gatherings.