DARIEN, Wis. (AP) – Just in time for the holidays, a Walworth County man has hit a million-dollar Powerball jackpot.   Roger Cobb of Darien missed the top prize in Saturday’s drawing by one number. He matched all five regular winning numbers but he didn’t get the Powerball.      Still, that was good enough to win $1 million. Cobb is taking the money as a lump sum, which works out to $672,500 after taxes.  Lottery officials say Cobb has declined to take part in a news conference, as some winners do.  No one won Saturday’s grand prize, which now rolls over to Wednesday’s drawing. The jackpot now stands at $500 million, or a cash value of $327 million.  Wisconsin’s last big Powerball jackpot came last month when a Milwaukee woman won $1 million.