128 gigs is more than enough to load 13B model into. Pytorch has M1 support for some time now so CUDA isn't required.
As much as I dislike the loss of socketed RAM, I have to say it's working out well for Apple users so far. I wonder if CXL will change the situation for consumer devices or if it will only be useful at the scale of a server rack.
128 gigs might even be enough for 65B, if slowly.