You can just tell the guard you want to look around AK Lodge for a future stay. He'll let you right in, and you can enjoy what the above poster mentioned. Your kids might also enjoy visiting the Allstar Movies..same thing..just tell the guard you want to visit for a future stay. It's a great picture opportunity.
The petting zoo is still there at teh campground, as is the campfire..but I think for the campfire you are suppose to be staying on site..but I'm not sure, and I have met up with people who weren't. One gal told us she asked in the store if it's allowed, and they told her sure..prob depends on who you ask. If you have hopper tickets, you are entitled to use Disney transportation, so you might want to park at T & T (you'll have to pay if you don't have an AP) and take the monorail to the Contemporary and then a boat ride over to the campground. Or go to MK and take the boat form there. The contemporary does give you three hours, if you want to look around there, maybe do Chef Mickey's and a quick visit to the campground at that time. We like to watch the electric water parade (we stay on site usually) from FW beach.
Boardwalk is always a fun place to visit in the evening..just tell the guard you want to visit the shops, etc, and he'll wave you through.
You can take the boat from POR to DTD as mentioned above..but I think to rent the bike's, you may have to be staying in the hotel. They did ask to see our key the last time..but that may have been because of the discount we were using.
Downtown Disney is always a hit with the kids..the toy store and the little playground are fun.
We visited POR from our Disney hotel last vist and enjoyed Bob in the bar area. The kids were having a wonderful time with him (and he sent his thanks to the Diser's who he feels got him his job back!) as were the adults..who he actually got to do the turtle on their backs. Boy does that guy work hard to make sure we in the audience have a great time.