When we thought we would give Ftiming a go back in WINTER ’07 in the TL, found out it id quite uncomfortable at near freezing temps in GA, NC, TN, MS, and even LA (January). Drafty, inside moisture buildup, little and non-ergo space as you noted, and short days. I would advise you bring that 5er down south for 6 weeks. Maybe trade 5er for a 17 ft HiLo trailer repurposed as a towable living room for TL.
Could try and get creative w/ a comfortable sofa-to-twin bed piece to sub for your uncozy wide dinette, and have a nice dinette table that mounts in the now wider aisle. Place table up closer to the front so as to leave it up all day.