Perhaps there's confusion here. A DVD (Digital Versatile Disk) disk can accept a variety of formats.
It your aim is to create a DVD DATA ISO, then the above 480 resolution test fit the disk... "...the ISO took about 25-minutes to create. Size: 3.73GB." This will play on a PC, but likely not on most standalone DVD players.
If you want to create an ISO for a standalone DVD player, choose DVD MOVIE. Using the latest VP release, that resulted in a 3.44GB ISO that took more than an hour to write.
Can't spot where you see an estimated export time, but don't put a lot of stock in the estimated file size.
As for fitting large files onto a single disk, look here.