The regular fuse panels only had about a dozen fuses, so you could eliminate certain circuits that need to be always on. Only about 3 or 4 circuits should be on switches like lights, accessories, headlights, engine. Small airplanes have a switch & circuit breaker for each circuit for safety. It's not a lot of switches (instrument panel doesn't look crowded). It sounds like you would want a battery disconnect switch inside the car, which is not uncommon.
Also, there are certain switches that contain integral fuses. Cool. 8)