I live not all that far from downtown St. Paul and had figured that our local places on Grand and Selby and West Seventh would be mobbed. So I resolved to stay as far away as possible. One night I was hungry for a particular sandwich at a place on Selby and called ahead to see if I could get in. The place was empty. So I went over and had my choice of tables. The owner was quite disgusted. Seems the local people were all staying away and there was no convention traffic. Same thing the next night at another place. Same story the night after that at yet another place. (I was going before 10:00 pm when the speeches ended but was told the places were not getting traffic after that either.) So it seems like the local places didn't benefit and may even have been hurt.
I would guess the big catering places and big restaurants where events were held in Minneapolis and probably the hotel restaurants did well but not the other small places especially in St. Paul.