Tell them the first floor is for medical needs - those are assigned first before people with the same request for 'non-medical' reasons.
Put your requests in order of priority to you. Room assigner CMs have posted on the boards that they do try to meet at least one of the requests people have and try to fill the first one listed if they can since they assume whatever was listed first was most important to the guest.
Here is a
link to the POR resort map.If you look it over ahead of time, it will help you to figure out which areas you are most interested in, which will help during check in.
One thing to keep in mind is that sometimes one of your requests (like near to parking) may be the totally opposite place to one of your other requests (like close to the food court). I don't know where the trundle bed rooms are, but from what I remember, they are not all over the resort, but just in some specific areas. Each request you make means some of the rooms that are available won't meet that next request. For example, there might be a lot of trundle beds, but not all are on the first floor. Of those on the first floor, not all are close to parking and of those trundle bed rooms that are close to parking, not all are close to the Food Court. Taking all the requests into account, there may be only a few rooms that meet all your requests and if they are already full when you get there, there won't be one left for you.
You mentioned that you are hoping to keep your wheelchair in the car trunk. If you don't have a room close enough to parking, I'd suggest you bring it into the room and keep it folded (I assume it folds or you would not be able to put it in the trunk). We have stayed at POR with DD's wheelchair in a regular room. We just did some moving around of the furniture (table and chairs) to make a storage space for it. She is not able to walk, so did need to be able to get around the room with it. It was a bit tight, but we managed.
You could also use it to get to/from the room and then have another member of your party take it back to the car for storage.
Since you don't need the features of the fully wheelchair accessible room, you probably don't want one. The room is the same size as a 'regular' room. In order to make the bathroom wheelchair accessible with a roll in shower, they change the placement of the wall dividing the bathroom from the sleeping area, making the sleeping area smaller and the bathroom bigger. This also means that many of those rooms have a single king sized bed - that's the size of bed that fits and still has room for diving around.
