OK feasibility, look at the floorplan of the unit you were considering, If you assume that all persons are willing to sleep in a single area, accept that the small bathroom will make toilet time limited for each person especially if privacy is desired for such times as changing clothes etc. Also look at the amount of room available for getting past someone in the kitchen area or trying to get to the rear bedroom. The widths of walkways are generally 2 to 2 and a half feet.
Also on the sleeping issue, is condensation, most people in here will likely agree that more than 3 people in a unit starts to get the moisture levels high just from exhaled breath unless a window is open or a dehumidifier is in use.
10 people in a 30' RV for a day and a half,,
Can it be done? Yes.
Will anyone have enjoyed the experience??? You decide, you know the 10 people.
On the width of the sofa beds, generally 50 to 54" wide mattress
Dinettes are generally under 6' long when made into a bed, width can be single or double bed width.