I wire in late winter, and I know Crust does as well. I don't know how it would react to fall wiring, but although I've read things about larch reacting badly to winter wiring, I've never had any trouble. Look up some of crust's threads, and I think you'll see that he has seen the same.
If you wait till spring you can damage the growing buds, and you'll not be able to leave it on long, as developing trees can swell so quick in the spring. If you do wire in the spring, watch it close, or wire it a bit looser than you normally would.