I can only think of three instances where you need the internet for BI related functions: 1) To download the software and register the license initially to get it out of "trial" mode 2) To download an update for the software 3) To view the cameras or get notifications while off site.
You will need to download and install the BI software and then register the license at a location that does have internet and then move the computer to the "off grid" location. In the same way, you could download any update you want to install onto a USB drive and physically carry it to the offgrid location, copy it over to the BI machine, and update the software that way. Obviously #3 is going to be impossible without internet, but the core BI system will work just fine without internet access.