Hi Jake,
Collinite 845 is a tried and trued wax that provides months of protection and yes, through a long hard New England winter.
I've actually applied it over a sealant and over itself. Personally, I cannot tell if one's better than the other or if one lasts just a bit longer....The bottom line is both ways work.
Whether Collinite over Collinite or Collinite over a Sealant, I always wait a day..
Tip
Regardless of the protection you use, it's important to wash the vehicle to remove the hazards of winter. I prefer warm rinseless washes then followed up by Duragloss Aquawax or something similar. By doing so it gives the protection a boost and this is always welcome during the winter months...