we just leave the heating on but set to a slightly lower temp.
That's what we did but I believe that with an iNET Box, it also allows those that store their vans away from home (in storage) to keep an eye on battery status etc. You send an SMS to the van iNET Sim and it responds accordingly. Not sure what else it can do though.
It works on Bluetooth and SMS I believe. The Bluetooth bit puzzles me, because if you have to be in Bluetooth range, why not just pop in the van to do whatever you want it to do. Maybe I'm missing something there though.
My van was either on site with me in it, or sat in my drive plugged in anyway so battery not an issue. On site, I'd paid for my electric so it's fair to say the van was never cold.