I concur with the advice to ditch the pad / Reflectix.

One other comment is me just repeating something I saw JustBill post on another social media platform -- he recommended stacking top quilts versus underquilts. He said the extra heat would be driven down into the underquilt and trapped there, giving you more warmth top and bottom. No personal experience with this but it might be worth a try. And easier to accomplish than stacking underquilts.