It depends--This doesn't feel like a very satisfying answer, but certain devices have been shown to perform better at extreme low temperatures (up to a point).

It depends--This doesn't feel like a very satisfying answer, but certain devices have been shown to perform better at extreme low temperatures (up to a point). However, there is the ever-present issue of reliability. For instance, certain CMOS devices exhibit improved switching characteristics, but the increased hot carrier mobility can cause degraded reliability, so certain design trade-offs have to be made. Of course, many COTS components specify much higher minimum operating temperatures in their datasheets, so thoroughly characterizing these components is vital for high-reliability operation in cryogenic conditions.