I have a crawl space that is about four feet deep. Bermed inside with vapor barrier then gravel on top of that. It is very dry but being unheated the floor above gets cold. Have been told to insulate the concrete walls above the berm (about 18") but not the ceiling as that would keep the floor cold. No heat below in crawl space.
Stop listening to whomever told you that nonsense. The walls mean nothing. However, you absolutely need to insulate the ceiling of the crawlspace. The ground gives off heat and the heated room radiates heat, you want and need to trap whatever heat you can in order to get a warm floor. Put Plastic Sheeting over the insulation and you now remove humidity and bug intrusion.