Remote Control of My Home Thermostat

[David]

I would like to install a thermostat on my home furnace that con be
programmed for various temperatures at various times of the day.  This
part of my project is easy.

But, I also want to be able to control the thermostat remotely.  That
is, when I'm not at home, I'd like to be able to change the
thermostat's programming.  Is something like this possible?  Control
via telephone would be the most convenient.

David