We (me, DH & DD6) went to WDW for the first time this past April. I was more excited than either of them too!
Since it was our first trip I went a little overboard and booked CRT & Epcot breakfasts.
CRT was our first morning. It was great! The setting was magical, the food was fresh and yummy (especially the stuffed french toast) and the princesses were very good (a little rushed but they are like that at both). They give kids their own plate including french toast sticks - a big hit with my daughter!
At CRT they call you up separately, per family. At Epcot, they must have a few sittings or at least the first of the day is like that. They let everyone in all at once. My daughter was a little disappointed because they have a designated "princess of the day" who has a special crown and wand and leads the girls in, while holding Snow White's hand. Food was hot & fresh but pretty bland. No separate plate for kids. No stuffed french toast either.
Like LAWalz23 said, be sure to allow at least 30 minutes from time you approach entrance to get to Norway. They let you into park early if you have an early reservation but you have to go through security first (took us 15 minutes) and the walk is at least 15 minutes at a brisk pace. At CRT the princesses seemed to work the room better. At Epcot they all moved from one room to the next so you didn't have any princesses at all, then you were bombarded by them for 10-15 minutes and then it was over!
Also, it was funny: I read somewhere that Cinderella NEVER is at Epcot so when my daughter said she saw her in the other room I told her "no, she isn't here." She kept insisting and boy did I feel silly when she walked into our room!! The other princesses at Epcot were Belle, Snow White, Jasmine & Mulan. No Sleeping Beauty or Mary Poppins.
An hour is probably enough time, although it depends on where you are seated. The room to the left was the first room the princesses visited. They were done in there within 45 minutes. The room straight ahead was the last one they visited. If you are seated there, you may need a little more time.
IMHO, I would try to get CRT instead. We really thought it was better. But, I think my biggest problem was that I kept comparing the two. Doing one is a definite must if your girls want autographs. We did not see the princesses around the parks much at all. In an hour or so, you will get at least 5 princess autographs!! The pictures are priceless as well!!
Above all, enjoy!!