I love the place. Don't love the food.
When we walk to the parks, we go out to the sidewalk, turn left. Cross Katella via that big huge crosswalk. Continue walking. You will walk amongst palm trees and birds of paradise flowers, on half of a gigantic hidden Mickey (look at google maps hybrid view of the area). Pass Paradise Pier Hotel, turn right into the Grand Californian's grounds. Enter the big gorgeous stained glass doors to the Grand.
To get to the esplanade, as you enter the lobby, turn left down a hallway (that I believe is marked for downtown disney). Follow the hallway (ramps for wheeled conveyances are to the left, when walking this direction), and at the end turn right through automatic sliding glass doors. Follow the outside path straight then to the left, and you'll soon be in the last half or third of downtown disney. Studio 365 is on your left and Sephora is on your right. Haagen Dasz is across the way. Turn right. Get to bag check. Go through to esplanade and pick your park!
It is more complicated to write it than to do it. It's not short, but it's not LONG either, unless your husband has convinced you to just rent a stroller for the 3 year old once you're at the parks, because it'll be too much of a pain to have the stroller at the airport. But the 3 year old did NOT agree to that plan, so needs/wants to be carried to and from the parks (while refusing the rental stroller...go figure!). If that's not part of your situation, it won't feel that long.
They have a small store on their property.
They charge for parking and for internet.
They have a lovely lobby and pool. They have always been very nice to me.