I have a momarsh cot that fits in the Cabela's intermediate perfectly. If your dog is wet, it drains the water away and keeps the dog out of the water as well. You can also use it for place training. I also had an insulated pad from fleet farm that fit in perfectly as well, but the dog chewed it up when she was a puppy and I never replaced it. I believe it was made by arctic shield. It was dark green in color.
Curious how this kennel has treated you (and your pup) since you have had some time running it? I am currently deciding between the cabelas gun dog and the dakota. How big is your gsp? I have a gsp and am not sure between a large and intermediate.
My griff is 50 lbs and I use a momarsh cot in the kennel and she fits in there perfectly. The Cabelas kennel tapers from the bottom to the top which is essential for getting the kennel in the back of my truck behind the passenger seat. I would definitely buy the kennel again. I believe Cabelas came out with a bigger size kennel this last year. If you live close to a Bass Pro or Cabelas, they have them on display...you could take your dog in and try them out.