Nvidia recently released the 331.82 version of their drivers for Windows.
To install them under Bootcamp (for late 2013 retina Macbook Pro) the same procedure as outlined in this post: http://sleep.dontexist.com/2013/11/01/installing-the-latest-nvidia-drivers-on-late-2013-retina-macbook-pro/ can be used.
Note: This assumes that you have already started the installation program once, so that the files are extracted to the C:Nvidia331.82 folder.
nvaon.infNote: See edit below.
Extract the file
Copy it to the C:NvidiaDisplayDriver331.82Win8_WinVista_Win7_64InternationalDisplay.Driver and overwrite the existing one
Run the installer again, it should now recognize the GT750M in the Late 2013 retina Macbook Pro and continue to do a full install.
I have just tested this and the install went fine. I have yet to test if there are any changes regarding games (i.e. Battlefield 4) etc. But the install itself went through fine.
Edit : According to comments from Danny and rbut below the installer should now recognize the card by default. I had an error when I first ran it, but that could just be bad mojo at the time. So, before extracting the file etc, give the installer a try and see if it works. If it should fail, then give the above instructions a try!