I use the outdoor temperature plug-in to trigger winter/summer.
If the outdoor temp>65, then cooling is turned on. If the outdoor temp<60, then heating is turned on. Very handy in the spring and fall.
I also used PLEG to set both the heating and cooling setpoints for Home, Away, Night, and Vacation. Home is set 68/75, Away 68/75, Night 66/72, and Vacation 60/80.