Picture the yard cleared out, the table set, and someone else handling the food while you actually get to talk to people. A catered brunch for a backyard bridal shower usually runs about $1100, and spring weekend dates fill up fast.
Timing is your real leverage here because spring dates book up months in advance. Lock in the caterer four months ahead so you aren't scrambling, and leave the smaller details like flowers and napkins for later.
That intro window is a hard deadline, not free money. If you still have a balance left on the Discover it® Cash Back when those 15 months are up, interest kicks in on what is left.