1800 miles in 3 days with 3 kids in a truck. Crazy or not

1800 miles in 3 days is totally doable if your trailer tows well. That's 600 miles/day. That was our limit when we had a TT. Even at 60/mph average speed, it's only 10 hours on the road. Your kids are old enough that they should be able to behave themselves. Just make sure they have plenty of things to do, books, laptops, DVDs, games, etc. and they should be fine. Ours are used to long drives, we've been doing 12 - 14 hour drives with them since they were very little.

Good luck and enjoy your trip!

-Michael