The Microsoft Nano Server Team just released the Nano Server 2016 TP4 In a single VHD (543Mb).
The VHD is available to download on the link below:
The VHD Is 543MB compare to the 5GB of Windows Server 2016 TP4.
Once you download the VHD copy it to a folder
Start the VM and press F11 at the Console to set the administrator password
After you change the password log in.
You can read more about the VHD release on the Nano Team blog: