I think this has been a surprisingly civil discussion of a topic that generally gets peoples knickers in a twist.
Pretty much boils down to same answer as the bathroom or no bathroom in the camper question. What works for you is the best choice.
I will mention something that has not come up. Commitment and escalation. A weapon escalates the situation, a deadly weapon always
escalates the situation to one of deadly force. If the other party brings the weapon then you have to decide if you want to go to that level. If one is not committed to that escalation don't ratchet things up.
Even pepper or bear spray against a person makes a fight with that person probable unless flight is an option. Breaker bar, knife, spare axe handle are not used to "threaten" someone they are used to injure, disable or possibly kill them. A firearm is by definition deadly force it is not a tool to threaten, wound or scare someone. Expect the other person to go to that same level of violence.
One other important point, you may well not scare anyone. You are a nice person, the person(s) confronting you are not. They may well figure you won't really act (shoot, stab, or hit) or won't be able to hurt them before they take you down. You don't confront violence on a regular basis, they may well be experienced at it and in their eyes you are a victim, not a threat.
My somewhat ugly 215 lbs. 6'1" self with a club in one hand asking if you would mind putting the generator
back where you found it would probably convince one guy, probably even two that they "made a mistake, wrong camper, thought this was our buddies camper". At three the gray hair might make them a bit more tempted to argue the point.
My wife being petite, pleasant, and cute would have a hard time convincing two guys to leave with a pistol in her hand. Darn sure not going to "scare them off" waving a can of pepper spray or a club around. Her best bet may well be to strike with total surprise. If god forbid she ever had to use a knife or club to defend herself I would hope the other party would not know she had it until they she had already struck at least twice and they were already going down, and any other target was already being struck.
Pepper spray hampers the other person it does not put them out of action so you better have a plan for what next. No action is best unless you have absolute commitment to the course of action you set in motion.
I think predatory people can tell when you mean business and when you are just hoping they will go away. Put another way if you won't shoot, stab, or beat one or more people into a hospital don't carry the tool that requires that and don't go there in an actual confrontation.