This is utterly a question of what you personally can tolerate.
A focused question like "Can I lessen parasitic draw to less than an ampere?" may get more specific results. Because my meters are switched LCD I can reduce quiescent draw in Quicksilver to <20 ma. But then my refrigerators are not gas and are not allowed to consume power when not actually running.
Thermostats
CO Detectors
Radios
Stereos
Clocks
Anything that tries to think with 12-volts is going to consume power. You need to audit individual circuits to find out what is consuming how much power...
Help could come from forum members who could declare "XXX is too much power for an xxx device"
It's worth a shot...
