As long as temperatures do not spike upward for prolonged periods, trails will remain skiable long after your driveway has cleared! Aggressive grooming has encouraged the frost to penetrate much deeper under ski trails. The resultant refrigeration effect can produce great spring skiing conditions.
However, classic and skating conditions are different and are best skied at different times of the day.
Best conditions are in the morning as the temperature is transitioning through zero degrees C. A frozen track is hard to skate on as the old skating marks make for an uneven surface. At this time of year grooming is often done in the early morning to remove the old skate groves and leave a thin surface layer of snow, that will not refreeze too hard, as long as temperatures are slowly rising.
Best conditions are in the afternoon when the frozen track is softer and more forgiving.