I don't understand the "problem".
The house is not rented out, just there for family and friends .......
Presumably you are concerned about cold weather. If you are looking at controlling the temperature remotely then, by inference, the heating/boiler, is on continuously. Most modern, non internet connected, thermostats have a "freeze/ice" setting that will automatically turn on the heating when the temperature drops below a certain level.
What am I missing?.
PS If internet connectivity is that important get a cheap T-Mobile PAYG phone that allows tethering, and for £20 for 6 months, get "unlimited" internet, and a WIFI hot spot for friends and family.
Edited by deleted (Wed 20-Aug-14 17:40:36)