From the RPR, the walk is too long, as it is on the other side of IOA. You can do it, but it will take 30 minutes. It's the equivalent of walking all the way from the RPR to the parking garage (about 20 minutes), then going across the street (another 10). If it's just you and the spouse, then yes, but if dragging kids, no.
However, you can walk from the HRH, and the PBH, it's about a 15-20 minute walk depending on where you are going. Yes, it's 10 lanes of traffic to cross, it can be done, just need to run across the street and pay attention.
http://www.nogodforme.com/offsite.htm
http://www.nogodforme.com/directionstopublix.htm
From the RPR, you can walk to Wet N Wild and there is a restaurant across from that, it's about a 20 minute walk over a bridge.
If you are coming in a limo, have them stop at Publix before checking into your hotel. Most will make a 15 minute stop as a perk for using them. I tell people to rent the car for the week, that way you can go anywhere, when you want.