Although a large gathering that includes a covid infected person has the potential to spread the disease to more people than a small wedding, I think the size of the wedding is not what we should concentrate on.
In the NY/NJ area, many have had it, perhaps most. If we confine our guest list to locals, we're unlikely to have anyone with covid at the wedding. So noone is spreading it.
A good friend is making a wedding very soon. I talked to her about relatives coming in from out of town. She's thinking about politely disinviting them.