I've solo backpacked with and without them, and to be honest, sometimes they make it worse. On trips when it was just me and Nikita, she would sit there and guard me, going on alert at every little thing. One night, up at Kermsuh Lake in the Uintas, I was sitting out on the shore under a new moon. I was shooting star trails listening to my camera click every 30 seconds. I kept thinking what a bad idea it was to sit in the darkness without making a noise and with no light at all. I turned on my red lamp and looked down at Nikita by my side, comforted by the fact that she wasn't like growling or anything, until I noticed she had a mohawk all up and down her spine staring intently into the woods behind me.
Meanwhile, when I soloed in La Verkin Creek, I actually had wildlife approach me in camp twice and I never felt uneasy about being alone. Similar up in the Sawtooths solo at Imogene Lake. Sure, I went to bed early, but I felt fine.
Fortunately for this weekend, having a second dog usually means Nikita will just relax and sack out on the boat. Sage gets upset if there is something she perceives as an imminent threat, but it takes a lot to get her worried about something.