Is there any reason you need to use Evoq?
In most cases the Platform is sufficient, esp. when using generic modules such as 2sxc - Dynamic Content and Apps for DNN (formerly DotNetNuke) or sachatrauwaen/OpenContent: Structured Content editing for DNN (Dotnetnuke) (github.com).
Of course everything works without an internet connection, except you use some modules that need internet access. Examples for this could be commercial modules that check if you paid the subscription fees, or extensions that request data from an API outside of your network/company.
Have a look at it and try it - it's free, so you just have to invest your time.