I have the full Rancho Longcoat, hat, mask, and gaiters. You need to get comfy in it as it's not a "normal" archery feeling for sure. Practice in it. Last week I just pushed my bow arm sleeve all the way up over my bicep, almost to the shoulder and strapped it down with the wrist strap on the jacket....I suppose I could also trim the forearm too, but don't want to chop it up yet. Wear a camo shirt underneath and the left arm isn't an issue at all. Use big rubber bands to hold down the shaggy material up around your bicep if not trimming is a priority.
The Rancho suit is warm, to be sure, and mosquitoes can't get at you while you're wearing it!