TT with bunkbeds

I have the Jayco X213 with the bunks up front and it has the king bed slide at the back. Nice thing about this unit is that the living area is 21'and it extends out to 27'. You can still use the washroom, kitchen and beds with the slide in. GVW is 5500 lbs I tow it with my 04 Dodge Ram Quad cab 4x4 with ease.

Perhaps older children would rather be in a tent.
Our Outback will sleep ten but it sure will not live ten.

Jayco X213 has bunk beds up front with a rear slide. And we tow ours with an Av as well. Having said that, our next trailer will be a Lance 2185-triple bunks in the rear.

You might get better suggestions if you provide the maximum towing capacity of your Avalanche. If you have one with the 8K towing capacity, you may be able to find a lightweight bunkhouse model that would work. So, I'd provide more info about your truck so you can get some realistic suggestions.