Get your taxes done using TurboTax

Well, of course you can.  You can do all kinds of foolish things if you wish.  

Should you?  Probably not.  The W-2 can have relevant information that's not on a final paycheck, information that can affect your income tax return.  Besides, the IRS isn't going to accept income tax returns until late January and you'll most likely have your W-2 before that.