We just got (4 months ago) a 2015 Winnebago Vista 31KE with a loft bed. Sleeps: a queen in the back (2), Sofa to bed (1), dinette to bed (2 / PIA), loft bed over drivers seats (1). So 6 can be easily done... we also have an air mattress that can hold 2 on the living room floor when the slide out is out, so in a squeeze would could hold 8 pretty comfortably.
That said, I am not sure how happy our "potty" would be with 8 working it...
Some will say the sofa bed is for 2, but only if they are small kids.
After 2015 you will find many of the smaller gassers (<32') have loft beds.
We just got back from a 5600 mile trip for 6 weeks... and the loft bed in the Winnie works great.. even when the teenager and DW have mis-operated it (did not follow instructions and it could have broken). It held up well.
Very happy with it.