Minimalist.  That puts you in a different place than the "bigger is better" folks...no offense intended to those recommending 30'+.  We are seriously getting into minimalism and after 50+ years it takes time to get there, but our goal is to declutter and settle comfortably into a 900 sq ft house for us and our disabled adult son.  It can be done.  We made the move to a 26' TT a couple of years ago and have commented that if it were just two of us, we could do that!  At 26' a half-ton is right on the edge.  Our dry weight is 5585 and GVWR is 6629#.  Our '03 F-150 with factory tow is rated for 8000#.  Agree you need to get all the numbers from your truck and definitely stop at the scale....will cost you around $15 to get the various weights.  When you know exactly what will work and leave you with about 1000# wiggle room, then start online looking at floorplans.  Our 26' has a deep slide, so very comfortable living area/kitchen/dining.  Wonderful bathroom and a real bedroom with a sliding door.  You might want to seriously consider a unit with a sofa bed with air mattress just for those times you're not planning on.  Minimalists don't add without subtracting.  When something comes in, something needs to go out.  Personally, don't see why 2 people could not be very comfortable with the size trailer you're thinking - I'm inclined to say more 24' - 26' - careful planning, commitment to staying minimal and enjoying a much less stressful lifestyle.  Minimalism doesn't mean "bare bones", it means doing what you need to do the easiest way with the least amount of "stuff".  I rather envy you.  With several obstacles in our way, we're a few years away from this dream....but oh, so ready.  Good luck.