how is it possible to save a file greater than 1 DVD to a set of DVDs 14.8 GB and then how does one recover the file from the DVD set
The easiest way is to create an archive of the file. And allow the archive/compression utility split the file for you.
Then you can burn each file to your DVD. You can just right click and select decompress once you have copied the files over to the destination for it to reassemble all files.