Anything is possible
I did the 12wbt and lost like.. not much.. just because I couldn't be bothered sticking to it! I just eat 3 small meals a day, no excersize because I cannot be stuffed.. and I breastfeed(I think that helps the most!)
I put on 30kg while pregnant and am now 5kg off my pre baby weight. What your planning sounds like it'll work a charm!