I kind of look at my dogs like I did my kids. Once you have the first one, you might as well have more. You are now committed to taking care of one, so another won't be a problem. You have to make arrangements for care, when you are gone. If you take them with you, you have to take, food, water, etc. So doubling that is no big deal. I would never have just one dog. We did for all of 3 days last year when Hamlet died and my husband called me and did not want to come home from work. The house was just too empty. My dogs all serve a purpose and that was my criteria for getting them. Cody guards and makes me feel safe. Max is our clown and makes my husband feel loved and wanted. Jake is our outgoing, friendly, never met a stranger dog and Max's playmate. They all have their place in our life and fill it beautifully. For me an only dog is like an only child, too clingy, too needy, easier to spoil. Not for me. If you are concerned about the barking, consider getting a different breed. Pyr's generally don't seem to mind who they share their lives with. Jake gets along just fine with Cody and Max. He's not good with small dogs, but all big dogs are just fine with him. Also, keep in mind that rescues don't necessarily know how a dog is going to react to your particular living situation. It can take a rehomed dog months to really show his true personality. A dog that was very laid back and docile in a foster home may suddenly turn into a territorial, dominant dog in a different pack setting with a different human and canine family. It happens, so don't be surprised. Good luck and I'm sure you will make the right decision for your family and dog.
Kathy