Intentional or unintentional relights?
I don't always intend to smoke a bowl from start to finish, and most bowls will be set aside at some point - maybe for a couple of minutes, maybe a couple of hours, or maybe even till tomorrow. Sometimes I might only smoke for three or four minutes at a time, other times it might be a full bowl.
As to unintentional relights, it depends what I've done wrong and how badly. Was I not paying attention, did I pack it badly, or was the tobacco too wet? If it's attention, what the heck, it's supposed to be relaxing so who cares. If it's the pack, I'll fix it up with a tamp and a poke, and I'll probably get through the rest of the bowl unless I choose to let it dwindle. If it's simply too wet, I'll put the pipe aside and try again tomorrow. I may fire up another pipe in the meantime.