You don't. You set up your open plan office, and you take what employees are left over after the ones who are skilled enough to have their choice of working environment. This is still quite a lot of very skilled employees. Leverage them as best you can to make enough money to give them offices.
Our solution is to keep everyone remote till we can build good spaces, however that is not possible for everyone. It seems ridiculous that people think there are only binary options here.
