I have now spent quite some time trying to fine offline installer download for Express SQL. Many blogs and posts note old links and locations which are no more. I just need path where I can get offline version as the server is within isolated environment.
I figured out myself... New installer is not really an installer but a means to launch download of media also. So run the express binary on system which IS online... select download media. That will download SQLEXPRADV_x64_ENU.exe which is offline installer.