I want to make the Merlot Pot Roast everyone has been talking about and I have a 3 lb boneless chuck roast. I want to serve 4 people, will 3 lbs be enough? I make brisket all the time in the crock pot and it shrinks so much and am assuming this piece of meat would do the same. I actually have 2 three pounders and could use both if I need to. Any advice?