Circuit Breaker Upgrade Complications
Even if the 150A breaker existed (and it seems like it doesn't), that's unfortunately just the start. You would almost certainly need to upgrade the conductors to and from the 150A breakers for the higher ampacity, and quite possibly the conduit in which they travel as well, which would involve significant expense. And then the main panel to which they connect may not be rated for more than 100A per meter anyway.

So I'm guessing your decision is likely to be upgrade everyone to 200A potential or nothing.

I'd be curious how this actually turned out...