We've seen as many as six at a time at ours. It's pretty clear we have several pairs in the area, not sure if they're all Baltimore orioles, though. We may also be seeing some orchard orioles and possibly scarlet and western tanagers.
We have the Merlin bird identifier app on our iPhones, it identifies them by sound or picture, the sound finder finds quite a few birds we're not sure we're seeing and it could be false positives. It finds red wing blackbirds nearly every day and I can't really say I've seen any in town, I have seen them out on country roads, sitting on fence posts.