Maybe not this year but as soon as it gets above 60* next year is a absolute max dose of poison ivy herbicide and a stout rake with a DIY 15' extension a viable solution?
I did the same for a huge gnarly multi limbed shag bark hickory covered in PI as it literally was the only tree I could set a stand in at a location I was seeing a huge non typical frequent. Unfortunately after my successful herculean poison ivy removal effort the land got sold last week of October and I never got to hunt out of that stand.
I wouldn’t even risk it with that tree. That tree is in an area where many trees have PI. Most not as bad as that one.
I did try cutting the vines on a different tree in the same area (used a machete), but I was told that the dead vines still hold the nasty oil in them. So I never tried. More cautious than brave.
Also, I wasn’t going to risk it just so somebody else could slap a ladder stand on the tree I prepped.