book a flight to see granny and either pay for it and collect miles or use cash and miles on Delta or use a chunk of points and go see her. DO NOT try and make this part of your Honeymoon Itinerary, you will wind up flying many extra hours and adding 3 legs to get home after a honeymoon does not make for good memories (even if you say hi to grandma). Hawaii is great but if you want to do it mostly on miles you need more points and time. I would suggest flying grandma in for the wedding. Honeymoon in south padre, all of texas is warm (heck it was 85 degrees in DFW today), and wait until next year to do Hawaii.
You can strategically get more credit card bonuses to compliment the points you have and look for openings well ahead of time. Hawaii has many islands worth seeing and after a 8 hour flight you don't want to come back after only a week. Maui and the big island have whales Dec-Apr. and if you save your money you can visit multiple islands and go on excursions and adventures while your there. They can get expensive (and don't fall for the time share presentation, it's not worth the things they give you) Even with the flight and hotel for free, other expenses will add up fast. Our last trip we paid more to park in waikiki than the rental cost...i think the car was $17 a day and the parking was $20-$30. $5 a gallon gas is a reality there. A good luau cost $40 a head, some adventures are cheap but others cost a good bit (i liked the helicoptor tours). On our honeymoon we visited 3 islands and stayed in hotels on Oahu, a private condo (check VRBO.com) on Maui, and a Resort on Kuaui. I'm just sayin if your going to do Hawaii save up and do it right, the first time....if you just want warm, exciting and exotic book an all inclusive hotel/flight package for under $1000 a head to Mexico. DFW is about the same distance from Puerto Vallarta and Cancun or Riviera Maya (2.5 hour flight).....just my 2 cents....congrats and enjoy