Welcome to the forum, ctdriver007. Keystone has various designations for RV's which they claim have protection against the cold. Yours has been labelled "Extreme Thermal Package". Other labels include Arctic Package, Polar Package, and other advertising gimmicks to make one think that the RV will withstand prolonged periods of freezing temperatures and you will be warm and toasty inside. One is also led to believe that all of your water lines and plumbing will be safe from freezing up.
You should know that probably none of your holding tanks or your water lines are insulated. The only "protection" your holding tanks and any water lines that run outside along the underbelly is (a) from the 1/4' thick black coroplast underbelly cover; and (b) from the small amount of heat generated by the furnace when it is running. There is most likely a 2" duct which supplies some heat to these areas.
If you examine the underbelly, you will notice that it has numerous openings here and there and therefore will allow cold air to penetrate.
I could go on but don't be misled by the "Extreme Thermal Package" label. It is, in fact, misleading at best. Wrapping the inlet water and sewer hose is one step you can take. Skirting is another.
There are numerous posts on the forum about this topic and what others have done to make their RV "winterproof". If you do a forum search using the search function, you will find many posts/threads about this topic. There are various search words you can use..."skirting", "underbelly", "insulation", "thermal package", and so on. Check out geo's (aka "Lord of the Underbelly") posts on insulating - great info for you to read.
Will you be away from your unit during the day/night and leaving it unattended? If you are, then you will need to take more measures to ensure that your pipes, etc., don't freeze up.
2008 Cougar 5th Wheel 27RKS
2005 2500 GMC Duramax