This is what I was thinking. There are dumbbell adaptations of most barbell exercises. I've been doing dumbbell deadlifts and the one-legged variant, as well as lunges.

They are certainly different and have a different emphasis and limitations, but for a lot of training goals they can do the job very well. And even the mini-gyms found in hotels and apartments tend to have some dumbbells, while the same access isn't there with barbells.