I have a vacation home with a 6 zone wirsbo hydronic system in a 4 inch slab (insulated underneath).  I have an electric boiler and am utilizing a demand controller from the energy company which gives me relatively cheap electricity on off peak hours.  My theory is when the place is unoccupied to heat the slab on off hours for 3 cents per kwh and let it dissipate heat during the day and not run the boiler at the higher peak rate. I would like to change the current wirsbo thermostats and convert to programable.  I could use the demand controller to accomplish this but I let other people use the cabin and it is too difficult to explain the demand controller.  I am hoping they can figure out how to run a thermostat.  There is a heat pump I use for backup (I need AC a few weeks per year).  So I have 2 questions:

1.  Will this work in theory?

2.  How do I wire a set back thermostat to the current 2 wire system?

Thanks in advance.