+1 to James' approach, we've been down this road as well and having a conversation has always worked better than any kind of "prevention" based approach.
Another option we haven't taken (but would consider if it came down to it) would be to add a dedicated "high usage" connection that people can plug into using ethernet instead of wifi to ensure they're connected to the right system during specific high bandwidth needs operations.
Personally, I'd look for ways to tie usage of that service to other behaviors, similar to how placing a kitchen or bathrooms can influence how people move through the space, or how mixing full time and flex desks can encourage more mixing and meeting new people. Turn a problem into a solution :)
-Alex