SteelWolf is right, we will have trouble finding the personnel to fill 5 more divisions plus support. Ten ain't gonna happen unless you draft them. I would oppose that at this stage.
As you pointed out, we had 8 (80%) more divisions in '91. We hadn't had a draft since the mid '70s. Today's population is larger too, although I'm not sure the military age population is, unless you count illegal aliens.
We Could do it.