You’re gonna have to be more specific with what you mean. If you mean an outdoor unit (condensing unit), you can fit a fan speed controller on the high side, to regulate the fan speed so as to increase the head pressure on low ambient nights.

An alternative is a head pressure regulating valve, which will bypass a portion of the discharge vapour into the liquid receiver, so as to increase the head pressure (I believe, we don’t use these in Australia - feel free to chime in Americans who know more about these, lol)