>>1862162As long as you have tree straps with multiple loops you don't need to worry about finding the perfect pair of trees. For my setup I can hang my hammock between trees that are anywhere from 2.5m to 4.5m apart, maybe further if I wanted to tie in some extra length.
And you really don't need giant trees. I wouldn't use a tree that I could fully wrap my hands around, but as long as it feels sturdy if you push against it you should be good.