I think it's been summed up very well here with all of the posts.
We use to travel with dogs all the time. We also left our dogs behind when we went out to do whatever....But, we made sure we did things so that the dog would not bother others. ALL of our dogs were good, no barking or causing any issues at all. Just very well trained.
When we would leave we left the heat/AC on. ALL blinds were closed. TV OR radio on so that the dog could not hear what was going on outside. We always came home to our dog sleeping on the coach and happy as a pig in sh$$t. No issues what-so-ever. I use to be able to walk in and use the bathroom and not wake the dog up. Now, somebody knocking on the door.....That's a different issue that I think nobody can help.
-paul