Something like this, maybe front wheel driven, with a removable plastic bubble hatch in the middle? Then have the bed be a reclining style thing that you can raise up to form a seat rather than a bed? So basically you'd have a long velomobile with a seat that reclines into a bed. Impractical, but would be an "all in one" solution. It could make for a nice relaxing tour as long as time and a chill attitude are on your side.