iphone 6s plus battery drain

hi generally my battery life has been rather good on my iphone 6s plus apart from when the phone is on standby overnight it seems to drain around 30%. overnight my phone does get quite alot of notifications mainly from instagram and facebook and i was wondering if this could be the reason for such a high drain in battery life?

when i turn off my wifi and mobile data my iphone only loses around 1-2% on standby. and if so is there anyway i can turn of notificatons for instagram and facebook without having to turn of mobile data and wifi