Disney will move your bags, but not you. I routinely switch resorts on each trip. I usually hand off my bags early in the morning...usually by 7am. Then, I head to a park until around lunchtime. I then head to my new resort, get checked in. My bags are never there...even though they will tell you early to mid-afternoon. It's always been more like 5pm!!! So, I prepare better now. I keep anything I am going to need that day....change of clothes, swimsuit...banking on not getting my bags until after dinnertime!!
If you really want to have access to your bags, then I would just take a cab to POR from SSR....shouldn't cost much. That way, you can take your bags with you, and they'll be at POR. If you get checked in, and find that your room isn't available yet, you can still head to a park, and head back to POR later. If you need something in your bags, you can get at them since they're already at POR.
