There’s a well-kept secret in all Ubuntu releases known as “netboot”. This tiny ISO installs over the net so often needs a hardwired network connection but when you’re done, all the packages are right up to date.
The mini.iso file for 16.04 64 bit can be found here.
Here’s a look at the selections for 16.04 LTS.
The MATE minimal install is the package ubuntu-mate-core
.
The MATE desktop install adds ubuntu-mate-desktop
.
I use synaptic to check dependencies of these to see what they have.
This install method is very popular in Debian, where this idea comes from I assume. Does it fit your idea?