If Trump wins the usual suspects will kick off regardless, however if Biden wins fair and square the right won't unless there is credible evidence of voter fraud which seems likely from reports I have seen.If Trump wins again I think you are right, things will kick off. Maybe a few weeks of riots in the usual places.
If Biden wins then the right will protest while armed to the teeth. Not sure if they will riot, but it is a risk. Rioting with fire arms is not a good mix and would be a worst case scenario.