Mandy,
First, let me say WOW!!! 17 days? Sounds like a great trip!
Interestingly, your question involves a topic (180+10) that I am a admittedly a bit obsessed about recently. I've researched this question a lot, and have yet to find a clear and consistent answer about it from Disney -- and believe me, I have asked many different Cast Members at Disney Dining.
So, to be comprehensive I'll give you two answers:
1) I think the Disney policy is that you are allowed to begin making your dining reservations 180 days before your check-in date, and if you are a resort guest you can also book the next 10 days of your dining reservations on that first date. For additional days beyond the first 11 days, you need to call Disney Dining each day to make those reservations.
2) In practice there are several different answers you might get from Cast Members when you call, depending upon their understanding of the rules. For example, some have told me that I could only book 9 additional days, others say 10, and others have told me that I could book beyond 10 days, if my reservation were longer than 11 days.
I guess the rules for 180+10 are confusing not only to you and me, but they also are confusing to some of the Cast Members. Let's face it, the Cast Members have so many different rules that they need to learn, that sometimes they might get a bit jumbled in the translation.
So, what's my final answer? I haven't decided yet. All I can say is that when you call Disney Dining you will likely experience a fairly strict interpretation of the 180+10 rules (my #1 above), but you also might get any one of a number of different answers.
Regardless of your exact experience making your dining reservations, I wish you luck in getting your first choices, and hope you have a fantastic 17 day visit!!