John wrote:
We got a new freezer - it's a John Lewis Frost-Free job. We keep it in
the utility. When my wife told the salesman this, he asked about the
ambient temperature of the room (which is very cool, not to say cold.)

He seemed to imply it would be better if the room that the freezer is
kept in should be warmer rather than colder. This doesn't seem to make
sense to me.

The salesman is wrong. The colder the air is around the radiator, the
less work the motor has to do to keep the food at the same cold
temperature.