openoffice vs libreoffice vs ms office 2016

Is there an Office alternative that will still work - without any loss of functionality - without an Internet connection? The real question seems to be: with 365 being so heavily pushed, will there be a version of Office in the future that will run off-line, not require a subscription (can be purchased outright) and does not present the possibility of being switched to reduced functionality mode when traveling to areas where The Internet may not be available or deemed too much of a risk to use (wireless at a hotel,etc.)

We do currently heavily use MS Office 2013 - and would soon notice the loss of functionality. A few more stipulate the cloud cannot be used under any circumstances. For at least two clients, putting data over the Internet is an actual breach of contract.

I have a number of clients who require compliance with some fairly stringent STIGs (Security Technical Implementation Guides).

I am looking for an Office suite that can work with MS Office files that does not require an Internet connection for installation or cloud access.

Openoffice vs libreoffice vs ms office 2016