I'm thinking that putting the rig in the bigger room would be better from an energy standpoint during winter. There is more space to heat, more ways to get air in or out and the thermostat is there. There are several things to consider but my brain is fried at the moment and I'm very open to opinions since I'm still new to this and not all that smart to begin with.
I guess you have to put it in the place where you or your children will not brake it

And where some fresh and cold air is available.
So maybe near a window of living room?