Welcome back, Robin!
I'm sorry, I thought you meant "different hotel nearby" like you were staying at Disney's Art of Animation which is in nearby walking distance to Disney's Pop Century, or Disney's Port Orleans - Riverside to Disney's Port Orleans - French Quarter.
The answer still remains the same, of course you can! You'll still have to check in with a security guard at the entrance to any and all
Disney Resort Hotels you choose to visit. A few years ago a big "secret tip" was to park at any hotel then ride a bus over to a theme park to skirt the parking fee, which of course is a no-no. Now the guard will check your ID and you'll be issued a three-hour guest parking voucher. You will need to provide a reason for your visit; we usually hop around for the various quick-service dining delicacies that can only be found at specific resort hotels but generally don't offer advanced dining reservations. Dole Whip at the Polynesian. Beignets at French Quarter. The 'Secret Menu' at All Star Movies. Some resort hotels even have their own tourist must-sees, like Disney's Boardwalk Hotel has shops and restaurants on the Boardwalk or Disney's Animal Kingdom Lodge has animal watching stations. But you can be up front and say that you're just looking around for ideas for your next visit, you missed an item at the gift shop, or you want to take a picture near the same tree you took a photo by 20 years ago on your Honeymoon, etc.
I've never had a problem in visiting other resort hotels, however I have heard that during the holidays the parking lots do get full and you might be turned away from visiting that hotel. You can always try another hotel, or you can always take a resort bus from Disney Springs or a theme park.
Now that we're on the same page Robin I do hope that this helped! Thank you for coming back to the Disney Parks Moms Panel, and we'll see you real soon!
~Kristen