Personally, I would be totally okay with a largely cosmetic day/night cycle as a compromise which in coop works similar as resting: all players need to agree to the change. as others said, night is already in the game (though i understand even a cosmetic day/night cycle can be a lot of work due to several factors), it would endorse modding and make more use of the already cool light/dark system, plus the immersion bonus (hey guys let's attack the enemy camp at night would be something cool to be able to opt for)
