Apologies if this topic has been previously covered but my searches came up empty.

Before my travel date, I will be in possession of award certs that are not currently in my account (both a MegaBonus 1-4 cert & the annual Visa Cat 5 cert)

So, if I make an award reservation now (using points) at a property that is set to jump to a higher category next week, will I later be able to retain that lower category award but switch the payment instrument from a points reservation to one using an award cert?