Any bait that I introduce to the lake I put in at the end of my session, especially if I intend to return the following days or in a few days time. As for the amount of bait, this depends on the weather. If we are due for a mild wet period the fish should feed so maybe 1/2 a kilo of bait can be introduced. I try to spread the bait rather than feeding one spot so that I am getting the bait to any fish that may remain in one locality.
With Winter it is guess work when the carp feed, be it for just one hour in 3 or 4 days, but they do feed. If you have timed it right and/or Lady Luck is on your side, you may get a bite or two, but more often than not the indicators remain silent. It can be mind numbing but as long as you have the right clothing and plenty of warm drink it can be pleasurable. The nights are long so it is short sessions for me, a flask and sandwiches and travelling light. Wrap up warm and watch the water.