I am strongly reminded of another time when a government plotted to forcibly deport lots of people to an extraterritorial-limbo island under their control, and I don't think it's too soon to bring it up.

https://en.wikipedia.org/wiki/Madagascar_Plan

When it was a refugee camp during the Haitian refugee crisis starting in 1991, it held 12,500 people. https://en.wikipedia.org/wiki/Haitian_refugee_crisis

https://en.wikipedia.org/wiki/1994_Cuban_rafter_crisis says during 1994 Cuban rafter crisis 'Around 20,000 rafters would be detained at the base.' but it does not say how many were held at the same time.