Adam,
They made bowhunting illegal here after I shot small game as a kid but before I came back into shooting heavier bows.
All I can tell you is that we did not generally shoot from tree stands.
I guess a poacher would still-hunt or use a natural ground blind.
It's what I would do.
But a lot of the legal shooting of deer was done on driven game, contemporaneous pictures often show the archer standing by a tree.
It is relatively simple to step out just enough to shoot fine past the edge of the tree with virtually no apparent movement from the point of view of a deer, especialy on a day when there is plenty of wind movement.
Gaston Phoebus talks about green painted hunting bows (definitely a plus with a yew bow that has a naturally bone white back), and about lower draw-weights.
I guess that would be an 80 to 90 pounder in those days. :-)
If you are comfortable and are used to a slight degree of offset, why not?
And if it is a weight you can manage when cold....
I have shot the longbow from treestands and worse on occasion and whilst it is certainly possible, it can at times be a little inhibiting as compared to shooting a shorter bow.
Rod.
PS: Whilst Howard Hill shot a heavier bow in Africa for big game, he is also on record as saying that 70lb or so was his prefered hunting draw-weight.