Well...San Diego has enough wonderful things to see and do that you could easily spend weeks there and not do it all, lol. Sea World, Zoo, Wild Animal Park,
Legoland, beaches, harbor cruises, whale watching, not to mention all the great arts and culture.
This link is NOT the best place to look for prices, but it will give you a good overview of what to do and where to stay:
http://www.sandiego.org/nav/Visitors Then go look elsewhere for the deals.
If you're doing the Sea World/Zoo/Animal Park route, then staying in Mission Bay is pretty close. They have hotels ranging from the 4 stars to "just a room". The Hotel del Coranado is really nice...and often less expensive than the cost of Grand Californian.
Staying on site at
Disneyland will mean you won't really need a car unless you're planning to do shopping or eat beyond walking distance. Grand Californian does charge for parking, so that plus the daily rental can up quickly. But...you'll want to do some price checking....you still need to get (I presume) from Disneyland to the airport to go home. If you're flying from LAX a taxi is going to be quite pricey, probably $100....Orange County airport maybe half that, but you can probably get a Super Shuttle for $20 per person or less, but be sure to reserve it in advance. So you'll want to weigh those options with the cost of your rental car and parking. Sometimes, I have found that renting a car for short term is very high rates...and keeping it for longer, even though it will just sit in a parking lot makes the "daily" rate go down so much that it's actually cheaper! I've even booked a rental for 8 days, and turned it on the 7th day because it was just cheaper to do that....and they don't change the rate if you turn it in early. Silly but part of the game. If the price difference is just a few dollars, you might want to also consider keeping the car just so you have that convenience....you could always take run to the beach for an evening walk....head over to the Disney outlet store.....go eat off the tourist path.....etc. Ok, and I'll admit I hate having to schedule shuttles.....sometimes I'm ready to get up and get going home...other times I want to just walk around DTD one last time and leave for the airport at the last possible moment. If you have to schedule a shuttle, you're stuck with the time you booked so no leaving early or lingering longer.
October weather can be quite nice.....typically 70s during the day, 50-60 overnight.......water rides should not be a problem during the day...night times can get cool so being wet may not be preferred with no sun to dry you. I'd say taking a sweatshirt or light jacket is all you need for after dark...no parka needed, lol. Hotel pools tend to be heated, so swimming in the evenings is do-able...it's the getting out of the pool and running for the warmth of your room that is tough.
Don't forget there are also Halloween parties at Disney during October (dates haven't been announced, but last year it was Tuesdays, Fridays and Saturdays I think). They cost extra, and DL will close early on those nights (7pm I think). DCA remains open, but of course gets a little more crowded with DL closed.
