The problem at night is keeping them away from you. If you don't zip up the tent they will make themselves right at home.
I don't use a tent but often spend nights in a divvy or simply roll out the bed roll and sleep under the stars. I leave the goats loose. They'll bed down, when and if they bed down near you. If too close just hit 'em with something. Rock, pine cone, branch, squirt bottle.
However when one snuggles up to your feet it's pretty comfy.
Not comfy if they step on you but nothing like a horse or mule.
When you disappear into the tent they get nervous and may get a bit vocal. I haven't had that problem and would be a bit cautious of things that go bump in the night that come in to check out the easy eating opportunity.
The only way to keep a goat where you want it is with a rope. Goats wear collars not halters. Simple give them some rope and a place to feed where they can avoid tangles and you're good to go. Keep them close to each other but not touching. If they can't see another goat they can get vocal. Drives me nuts.
They don't wander far from where you are. At lunch time they are within 50 feet usually, if there is good browse. They usually lay down and chew their cud.
When you are up moving around, as when I'm validating LR drops in the mountains they graze and take life pretty easy and stay within 100 yards or so.
If anything spooks them, such as a pack of bear/cougar dogs they are pretty quick between your legs. Has happened to me several times. Met some nice cat hunters that way.
Saanans seem most vocal but only certain blood lines. La Manchas are quietly vocal. The Alpine I had was pretty much silent but a PITA to have around. The Nubian cross I had was the dumbest goat I have ever seen + could be considered on the lazy side.
All in all its a darn good experience.