You really should make ADRs for all your meals. It might not be as bad in Oct as in June, but you don't want to be shut out.
You can definitely find places to eat if you don't have ADRs, but you might have to leave the park and go to a hotel restaurant or DTD or the Boardwalk.
If you just want to eat breakfast at your hotel counter service or non-character breakfast at your hotel (e.g. Captain's Grill at Yacht Club), you would be OK. But any character breakfast or popular breakfast (e.g. Kona Cafe), you should definitely get ADRs.
If you do end up getting the DDP, definitely do ADRs so you don't "waste" one of your credits because no availability at restaurants.
If free dining is offered during your time, definitely do ADRs as the restaurants are especially busy then.
If you have an idea of where you were thinking about going, we could let you know if those are places that really require ADRs.
Maggie