[toss1]

Yup, it could really go down that way.

When animal populations overbreed and/or their feed under-grows, a 10% overpopulation often results in not a 10% shaving of population, but a 90% population crash, because almost every animal goes under the survival budget.

It would very much the same here.

Excellent point about the EEs (and other high-capability engineers, mechanics, technicians required to keep it all running) being in the dying population. Absolutely right - if the critical mass of available experts fails, the system never recovers. Only after society stabilizes, regrows, and re-creates the knowledge; by then, it would be about rebuilding from scratch.