traveling long distance

Well,

you have to solve the issue of food and water for them and be willing to accept that they will pee into their bedding (mind the persistent smell).

Our goats aren't comfortable with eating while travelling, so your second day would be quite hard on them unless you take brakes in between and either offer them hay or let them out to browse.

Is there a reason while you drive such a long distance on the second day? Could you divide it and drive a bit longer on the third day?

Not drinking enough could cause problems with urinary calculi in wethers.

In Europe the maximum travel distance for livestock is 8 hours than you have to make a mandatory break.

The longest we have gone with our goats in a trailer without letting them out was around 6 hours. Our's will eat hay if it is not getting soiled on the ground - when they just get in, and it is clean, or if there is a big pile then they will happily keep nibbling for as long as it lasts. A drink every four or so hours helps, though normally they aren't that interested. We also put branches in, which they greatly enjoy. If you could keep plenty of hay off the ground, give them plenty of branches (we hang then on the trailer walls) and water them however often seems reasonable for the temperatures and individual goats, you should be right I think. Ours also get a handful of grain when we stop. The goats do lay down, so hay where they can reach it while laying down would be good.
The only other major thing would be keeping the floor clean - if you take sacks of hay with you, and have places to dump the hay once (or with lots of goats) twice a day, that would probably keep it pretty clean. If you get the goats out several times for a 'toilet stop', that will help keep the trailer clean as they like to go to the toilet straight after getting up.
Cheers,
Cazz

WE bed the back of the pickup with a product called stall dri, then two bales of kiln dried shavings and two bags of wood pellets like pellet stove fuel. This all goes down over a rubber mat. THis keeps it pretty dry for a week and makes it less shocky on their legs.
It has a lot to do with how well the goats travel and will they lie down. I've done three day hauls when a goat stood the whole way while the truck was moving which is really hard on them.

They should have hay bags in front of them all the time. You don't necessarily have to unload them but stopping every hour or so for a few minutes will let their legs rest for a minute. And then a longer rest in the middle of the day. We expect to be able to make around 3-400 miles a day when we travel.

Get them accustoned to drinking gatorade water before you leave. That is the best way to get large amounts of water into them. But don't wait till the trip to start.

It's better if you let them out for awhile every day but I have hauled up to three days without unloading. I also have a battery operated fan that goes in the back when it's hot. It sprays water also. Keeps the back significantly cooler.