Not a 787 but on a recent 10 am departure from London they had served food and had all the window blinds shut by 1200 UK time and they stayed shut until about 30 mins before landing. Any transgressors were aggressively told off by the few cabin crew who were not snoozing off their night out in London
Same experience on UA 767 LHR to Chicago. (Probably the smallest IFE screen I've ever seen too!)