m1 max 32gbs or 64gbs for fusion?

Any idea if I can get away with 32gbs using the new m1 max for fusion?

the more memory you have the more frames can be cached, the faster you can work.
For example if one 4k raw frame takes 32GB and you might want to have 5 nodes cached in your project, then 1 frame will take around 150MB, or 8 frames per GB of RAM.
The short answer is, there is no such thing as too much RAM for Fusion.