The closest study I've found for carbohydrate/protein ingestion post-workout was a study done with gymnasts. They found that .4 grams carbs/kg + .8 grams carbs/kg within a 1-hour timeframe was optimal for recovery. As they are likely in a more catabolic state than weightlifters post-workout, I think this formula would apply fine -- it's what I use. For a 200 lb individual, this equals 73 grams carbs/36 grams protein. 225 lb = 82 carbs/41 protein. 250 = 90 carbs/45 protein.
As an aside, you body doesn't respond to steady-state protein feeding -- if so, the pros would be hooked up to an IV all day long (indeed, this is how they did studies on the subject). You body responds to protein pulse feeding -- a relatively large ingestion of protein at one time, followed by a period of fasting. In a steady release environemnt, the response curve to protein is about 3 hours, that is, your body utilizes protein well for about 3 hours post-ingestion and then the response rate drops significantly. It is better (for the purposes of hypertophy) to just ingest relatively fast-acting protein (whey being preferrential to casein) at regular intervals. As far as nighttime, it doesn't appear that a lot of catabolism occurs during this period of fasting, but you could always wake up in the middle of the night to down another shake...