How much do you typically spend per month on the card? Given your goal is less than a year away, if your spend is low, you may be better with a Disney card (which may have lower award levels) than an airline card (which typically starts at 25,000 miles/dollars per ticket).

Have you checked if your mortgage payments can be charged? Most can't, unless you go thru a 3rd party service that charges fees high enough to make it un-worthwhile for the miles earned.