Please advise if it's okay to sleep all day with a cold and hangover?

What do you mean ok?: If you have to get to work, or you have children to take care of (or other responsibilities) spending the day in bed would not be "ok." if a person is drinking enough on a regular basis to cause hangovers, then that person is drinking too much. If one routinely has to avoid one's personal responsibilities because of impairment of hangovers, that is an alcohol problem.