Do black hole singularities continually reduce their size due to their own gravity (given they have sifficient mass i.e. supermassive black holes)?
Could they become so compacted as to stop or severly limit sub-atomic particle movement and become cold enough to go sub-absolute zero?
I agree with RTtraveller..their size,theoretically, would increase with consumption of matter pulled into their gravity well, say to the size of a grapefruit, though at some point they stop "eating". A great example of this is the Super Massive blackhole at our galactic center, which has stabilized. As to your question of the freezing of sub atomic particles..the answer is No, the heat generated within the singularity is so high it actually shredds All forms of matter into a primordial "soup" of energy.