For our April trip, we're not planning on booking a package this time around, but I was just curious as to whether we could change our mind at check in and switch to a package with dining plan, or if that would be too late?
Check in is too late. The front desk can't create a package, you need to go thru the reservations center for that.
Register on WDWMAGIC. This sidebar will go away, and you'll see fewer ads.