I am no expert by any means, but I did read on here that you can request a "deep clean" because of allergies. Explain about your son, and I bet they will accommodate you.
I also read that room requests should be faxed in about 48 hrs ahead of arrival (there is a number here on Disboards for the room request fax line--someone more savvy--help please?!) with the requests prioritized as to importance.
I think a ground floor would help with strollers. We stayed at CBR several years ago with our 2 year old grandson, and between the walking from the bus stop and then carrying the grandson and stroller upstairs when everyone is pretty beat it was kinda
But the view was nice!
There are pros and cons to everything, but this time we are staying at POR and requesting a room closer to things and a first floor. If we get it, great, if we don't, we'll manage and there will be something else to compensate for it, like the view being better from the second floor!