I typically don’t turkey hunt too far from home, so I typically just bring them home whole and then pluck / gut / and then process them there. If I am camping, hunting more than a couple of hours away, or plan on hunting more than a few more hours longer that day, I will pluck the “belly” and the throat and gut them in the field or at the truck, if it’s going to be more than say 5 or 6 hours before I process them any
Further I will throw them in a cooler on ice and transport them that way. It’s nice if you have some clean water to rinse out the body cavity too, particularly if you won’t be able to process the bird for a day or two. When I process turkeys, I prefer to pluck the whole thing and then part it out, leaving the skin on the parts when I freeze them. (Especially the legs, thighs and wings) because it allows for a few more options when cooking later and you can always easily slip the skin off after thawing if you need to. It’s definitely more work, but it seems worth it to me.
I know the regs say “feathered head must be attached”, but I also leave the beard attached. Technically the beard is the only thing you need to see for a Turkey to be legal (I have no idea why they want to see the head when the beard is what defines legal vs not).
Side note: I have killed a couple of bearded hens in the last few years, and I wouldn’t hesitate to do it again. Although they certainly have less meat than a big old Tom, they are infinitely more tender. We even roasted one whole just like a thanksgiving turkey and she was great. If you do end up with a bearded hen, just make sure you leave the beard attached otherwise a warden would have no way of knowing if you were legal or not (and might err on the side of not legal considering that the vast majority of hens in WA do not have beards).