Sorry but at 20ft you are not going to get an over nighter for 2 in a cabin form. The TC601 is I think about 1.2 metres at the widest part of the bunk, it's big enough for 1 1/2 people which is a bit inconvenient for the second person and the underwater sections have had to be designed wide and fat to even get that width. It does have a great big cockpit area though which is bigger wider and long enough to say that would make a great camping area under a boom tent.
What the TC601 had always been designed to do was to give enough space in the cabin to give shelter if needed, a place where the good ladies and rug-rats could do what they needed to do in privacy, give light weight hull forms which allow easy ground handling and cost about 1/4 of its nearest rival the Pulse in components. That leaves a lot of spare cash for hotel and motel rooms when you get to where you are going to freshen up and have a nice meal.
We just need to think out of the box a little and consider how these 20 footers are going to be used before limiting ourselves to conventional designs, that's why in my opinion few 20 footers have been sucessful as designs to date.
