I have 6 footers and I usually have some strap left over.
Most of the trees that you're going to hang from in this part of the state aren't too big around. Sometimes you may need the extra strap due to distance between the trees, but you can usually find closer trees nearby if needed.
I like to err on too much strap than not enough. The weight difference isn't important to me, but I don't count grams all that closely.
If your lucky enough to be outdoors, your lucky enough!