Low temperature Semiconductor issues
This is researched under LTE (low temperature Electronics for deep space applications). Current electorincs for deep space applications use heaters to keep temperature in operating range.
Most semiconductor devices exibit improved performance at lower temperatures because of increased carrier mobilities due to reduced phonon scattering, increased saturation velocities, reduced junction capacitances and line resistances, and increased substrate and metal thermal conductivities
The key here is reduced resistances, reduced capacitances, higher Beta in transistors etc. IF your circuit has a built-in PLL, DLL etc. chances are it will work faster. The lower range of your frequency response will be higher. If your circuit has internal pullup resistors etc. they will have lower resistance. If it has analog circuits internally such as opamps etc. they will work closer to perfect due to increased beta.
The crystals actually get affected from the temperature too.