Each situation is different.
In my case, a bank big enough to start my engine is more than large enough to run all lights all night. I have changed all lights to small LED and fans to efficient computer fans. I also recommend a blinking blue light in addition to nave lights and it runs on two type D batteries for a month.
Each of my banks is 440 amp hours. Previously I carried 1600 amp hours and wasted a lot of fuel
just trying to keep a bank that large fully charged. Batteries consume power just sitting there doing nothing and a big bank consumes more.
You are right about an autopilot needing juice if sailing at night, however at night either:
are up and wind generator
is adding power.
B. Engine is on and there is no wind
At most I found I had to run my portable Honda
1 hour around 4 am because sails
were up in light winds and autopilot consumed.
consumes little at night.
Chart plotter is called my laptop
computer and provided I dont leave it on, it runs off its own battery in standby mode no problem.
is only turned on seldomly.