I would prefer Saturday afternoon just because I don’t like driving at night, especially since DC is more than an hour from home for me.
Just tossing this out there - before I left Florida, we had a fest in a park where we met up, brought bag lunches and hung out. I liked it because no one was trapped in a seat in a restaurant - you could socialize with everyone. I would gladly offer my place as a venue, but since I live in the boonies, I expect it’s not a popular option.
So that’s my 2¢ - I will do my best to attend, even if it’s an evening in DC. But, in closing, vote for PICNIC!