Wow, I'm impressed! What do you work on where 1,000 projects in a solution is a thing? With just one developer per five projects you've got a team of 200 developers. What are you working on? Please give us a few details.
why couldn't you break it out into separate solutions and reference versioned dll's?
It always amazes me how someone can say "x sucks" and never question their own insane workflow.