Personally after smelling it I would react prevention and response wise on a worse case scenario basis. It will dissipate normally under ideal conditions. So will Carbon Monoxide too if allowed. Wood smoke also wants to rise and dissipate under Normal Conditions. Watch it as a front moves through though how it hangs close to the ground.
Normal Conditions are usually not what kill you though. It's just like when a low pressure system comes through you have to take extra precautions with using gas powered generators and vehicles etc around structures.
BTW I was also a fire fighter at one point. That training saved my life one night in a way not many would even think about. I had a kerosene heater going in my storage shed. It wasn't insulated and I left the door well cracked. The door likely by wind closed. I had been sitting down and felt a little light headed. I looked over at the wick and it was going dim. I dove for the door at that point. I knew it meant lack of oxygen by how the wick was acting. That was because I used to test for explosives and survival O2 levels with what was called a mining flame saftey lamp. Not something I had expected to happen but it did.
Being the guy that people call when they have gas problems, and dangerous gas situations, I manage to get by. If you call the gas company first, then they lock the meter and make you call me before they will return your service.
You understand that, that means calling the plumbing contractor, which is me, right?