I have stayed at Grand Californian by exchanging
DVC points for a regular room (through the Disney Collection). And I have used DVC by going online and booked 2 bedroom suites, twice, both of them exactly at the 7 month window. (Because my home resorts are in Disney World.)
It is NOT a good use of points to do it through the Disney Collection. I have done 2 regular hotel rooms that way, at 3 days each, and if you assume that each point is worth $15 (because that is what you can rent them for), then the effective cost was 340 points, or $5,100 total or $2550 for each room. (Again, that was for 3 days each. What the cast member was talking about when they said that they would 'accommodate you in one of the other hotels' was for you to use your DVC points through the Disney Collection, and, instead of staying at Grand Californian, staying at
Disneyland Hotel or Pixar Pier Hotel (or whatever they are currently calling them). Those hotels cost a bit less, in points or in cash, than the Grand Californian, but they are still very point expensive. Frankly, I have a vacation scheduled there about mid-November and I will be staying at Pixar Pier Hotel and paying cash. I didn't rent out my points to get the money to do that, but that is something I will probably do in the future, and you should consider it, too. It is more cost effective.
If you want to get Grand Californian through DVC, then I suggest you go online at 7:45 AM Eastern Time, on the day you want to do it, and be signed on and ready to search as the clock rolls over to 8 AM eastern time. You will only have a few seconds, literally, to get a Studio or a 2 Bedroom Lockoff. I was unable to do that, so I got a regular 2 bedroom the 2 times I did it. A 1 bedroom MIGHT be available for a bit longer.
One other thing, and I almost hate to mention this: If your dates are very important to you, then you might do the 7:45 AM Eastern Time thing every day, starting about 5 days before you plan to stay. Keep trying until you pick up what you want. And then 'walk' it into the time frame/days you want. I hate giving people ideas, but it is possible. How much do you want it?
Grand Californian is amazing and wonderful. If you use Disney Collection points, ask for the Brisa Courtyard. But it IS NOT EASY or cheap. If you book an actual DVC room, those rooms are on the other end of the hotel (NOT near the Brisa Courtyard) and might overlook the pool, some nice trees, the road, or across the street to the other hotels.
Here is a picture from our hotel room, looking out into the Brisa Courtyard