I've done both woods/desert and campground with up to three big strong drivey dogs at a time. It keeps you very busy even with 2-3 people wrangling that many dogs at any given time, especially if you are somewhere you need to be on leash and there are things like obnoxious other dogs and stuff.
I don't think I'd take more than 3
with help and even just doing a non-camping trip with my two very well behaved girls last weekend I was extremely glad I had help from the friend I asked along because no ac in my car and ya gotta go the the restroom sometime.
On the plus side Lily was a lot less shitty during feeding time than she has been on past adventures, I was still pretty anal about having my friend hold Lily (I fed her first since she's a fast eater) while I fed Scout a ways away. I think Lily was just super pumped and happy to go on a roadtrip again lol, its been a while.
I actually got some portable chains made for camping in the woods. Usually they are only tied out while we're setting up or cooking and otherwise are loose or leash in hand depending on where it is.
I've only used the 15ft (I have a 10ft as well) one for Scout while huckleberry picking. I wanted to keep her close since she looks wolfy and well its ID. Worked a LOT better in the woods/brush than their long lines or cables have in the past. Lily was just in the bushes with me eating berries, so wasn't really worried about her. They didn't get to go this year because all the times we went, all of us went so there was no room in the truck.
I have to tie the tent zippers shut with a shoelace because Lily undoes them.