Today I’ve been making the first tests with lighting up the lanterns.
The lanterns are all instances, and the lighted ones had a Point Lamp to give the light.
Full of confidence on my instanced lamps I turned everything on and switched to rendered mode 
…
It could only went worse if the computer had actually explode, because it not only crashed blender like the entire computer.
So, I’ve slow down and the first thing I did was disable the shadows (shadows in more than one lamp makes all slow immediately) on the Point lamp; deactivated all collections except the island mesh and the boat docs and this shown up:
Back in business I thought
…So I’ve activated the houses collection too and:
All the docs lamps turned off
The problem seems to be that Eevee can only deal with 128 lamps, even if they are all instances.
Also all these lamps and Volumetric fog don’t go well together and crash everything up again.
The candle light has a material on the flame that emits light, so a solution may be increase the emission value and bake the lightning, but that not only takes 5 hours to calculate but also increases the file size from 5Mb to 1000Mb. There should be an option to save the cached light info on the disk, but so far there ain’t (as far I know).
… Night time needs more thinking 
The easy way didn’t work.
See you guys on Monday! Have a great Sunday! 