Good posting and topic as it conceens a lot of us on here.
Had had this happen to me a few times. Last year walking on public land near my house to an area 2 miles back in off of the road and guys come up to me and say that I am walking through their hunting area ( These guys live over 100 miles away btw) . Public land means for the public. Really po's me when guys leave their camps up 2 months before season "claiming" their hunting area. Now, when hunting if I see a guy on a stand I move on to a different spot. I never crowd other hunters
I would hunt the area and let the guy know. Sounds plenty big enough. If the guy starts making threats or damages equipment, have seen this done, document and call law enforcement. Don't let the guy push you out of the area. Plenty of room in your area for 2 guys. Who knows could be a lot more guys showing up when the season opens and that is a big possibility.
I would start looking now for escape routes when the buck gets pressured. He is going to change his behavior based on my experience hunting Wt's and might even go noctournal. I would get an idea of his patterns and limit your presence in an area so as not not leave scent. Find a few good areas to hunt based upon wind direction and only go back to hunt IMO. If the wind isn't right don't hunt that stand. The big boys get big by making few mistakes.
Good luck!