21 F is not cold ! But different things happen at different temperatures. Condensation can be a problem below 0 F. Cheap petroleum based lubes may have waxes [parafin ] that precipitate and gum things up.Stainless steels eventually may cause a problem but Crucible's 416 R is good to at least -40 F.
Many in arctic conditions don't use lubes to avoid problems and never bring guns in and out of warm cabins to avoid condensation. Keep things clean and LIGHTLY lube !!
And Watson , bring your revolver !