Agree with all who say Artic package is marketing hype not reality. We are living full time in Northern CA and many drafts, insulation where? would take multiple post to list each leak, lack of insulation etc...
As far as furnace intake as post describes, we have a 2017 3456RL and beneath the hutch is where the intake is located and get this its on the floor and no filter or screen of any sort so God forbid if anything gets sucked into that intake and gets torched by the running heater! Talked with FR about this and they said its by design and I can fix it which I did and the rest of the leaks. Sad response yes! and poor quality build.
But you own it now so you can either take it to the shop for the next few months or grab some spray foam, insulation, foam cord etc... and spend the next month weather proofing.
Welcome to the wonderful world of RV ownership, $0.02