Come on, in this day and age you wouldn't see that! Flights to Novak Airport would be at least twice daily on Envoy E-175s. You'd probably see Endeavor bringing CRJ-900s from Minneapolis and Detroit, GoJet CRJ-550s from ORD, and maybe even a Southwest 737-700 to Midway. While the airport and city don't reflect this at the moment, Van Buren would be a sizeable population center when completely built out and the additional traffic due to the government center, as well as the lack of other large airports in Superior, would call for a change in methodology for the airport. Instead of being a County airport it would likely become Novak-Van Buren Regional. KNVB is actually vacant, although typically the identifier is based off of the person or place it's named after originally. Hence O'hare being ORD, after its original name Orchard Airfield, or MCO, Orlando, which was originally named McCoy Air Base. Therefore, I think the code would be KNVK, which is also a vacant code.
Regardless of that TLDR, there's also the consideration that CWC now exists nearly 200 years in the future and you definitely wouldn't see E-170s then.