Peter Clark wrote:

I suspect it's something similar to the DirecTV system. They send
down authorization packets for (youraccout/deviceid) every
(onceandawhile). The device receives the packet, updates the expire
date, is happy, and keeps working. If you don't use it in
(morethanonceandawhile) the authorization packet times out and you
have to either ask them to send a packet specifically for your device
to hear, or leave it on for (longenoughtogetanewpacket). They don't
stop charging you for the service because you decide not to use it (or
in the case of DirecTV, have the receiver unplugged) for a month.

DTV has an alternative connection through the telephone...

Perhaps there is a 'seasonal suspend' feature they have available,
but I have no knowledge of that.

They do, its called a "vacation"... Takes a phone call...