That's fair (re: 64-bit) and I'll amend: VS2015 should be able to handle a solution with (say) 1,000 projects without crashing. If that can be done in 32 bits, hurrah.
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.
I'm working on a legacy desktop app (~25 years), currently around 600 projects. Maybe one developer per 7 projects. Common workflow is to create custom solutions around your working set of projects, but that's not ideal for whole code analysis/debugging.
Does that mean that there's a lot of duplicate projects? It seems like there's an opportunity for consolidation. I've seen a few solutions where a developer created a Project for every class library and then only ever referenced them from 1 other Project. I was able to roll up a 30+ project solution into 5.
We had ~150 projects across about 1M LOC and 4 developers because they were being used like folders - they weren't really separate codebases, just a means of organising the code. We cut that down for a drastic improvement in speed.
its not that uncommon to find VS solution files consisting of 100+ projects, especially in finance. The most I've worked on was 132 projects in a single solution (roughly a third were test projects). It was slow and sluggish at times but still workable nevertheless...