I don't think the DF 21SW has really changed all that much over the years. The rear bed should lift up out of the way, the sofa should fold against the wall as well. Should have plenty of room either up the middle or probably a tight fit side by side under the rear bed. I seem to recall the KQs were narrower then my Sportsman so I'd think you can probably get them in side by side if you had to.
Here is an older thread with photos from a 2004.
link
Two Wire Fox Terriers; Sarge & Sully
2007 Winnebago Sightseer 35J
2020 Jeep Gladiator Rubicon