You're right, it is a big swing. A difference of 7 wins over a 15 game stretch is gigantic. So yeah it's really not much of a prediction. But we have a very tough schedule ahead of us.
We have 7 road games, most if them against teams that could beat us although we'd likely be favored in the 2 OKC road games and probably at the Lakers too. Then, with the 8 games at home, we have Milwaukee, Orlando, Philadelphia, Denver twice, Minnesota, the Spurs and the Clippers.
If we keep healthy the players that are currently healthy, I could see us winning 3 on the road and probably 4 at home. So if I thought we could keep CP playing well and Booker healthy, I'd probably pencil us in for 44 wins. And as many as 48 if KD comes back early and healthy. But considering the way this season has transpired, I'm expecting no KD and for Booker's leg to fall off any day now - in which case we'll be lucky to reach 41 wins.