Too Narrow for a Viv?

Hey guys, I'm about to get started on 3-4 snake viv and I have a question:
I got a real good deal on the boards but the problem is that they are only 11" wide. I'm thinking about making each enclosure 36" long, 15" high and of course 11" deep. Is 11" too "shallow?" I can always bump the length to 40" (or more) if I need to increase the total square inches, but the only option I have to make it deeper is doubling the boards which would make it 22". I can do this but it's gonna make the viv harder to build and of course will use twice the lumber.
Just wanted some thoughts, thanks!

11 inches isn't too much shorter than the short side of a 20 gallon tank. So it should be okay. I would increase the length to about 40-48 inches so that the snakes have more floor room, but that's just me.

Thanks, I'll probably make it at least 40" long.

My multi Chamber viv is 4ft wide and only 14inches deep and 12 inches tall so I would think 11 inches would be fine, it isnt much shorter. It is a bit on the thin side but ok. Shoot, the 29 gallon that I use to have my corn snake in was only 12 inches wide.

11" is just fine.

Thanks guys!