walking space

As said make it yours.  Personally I have become accustomed to the small head and wouldn't want it different.  I am full sized (6', 275) and can do anything in the little head that it was made for.  I did have to leave the door open the first couple of times, but now that is fine.  And I want both the toilet and the shower because at times we camp where there are neither available.  To each their own.

Have to agree.. the slide in the 177 makes ALL the difference.

But.. honestly.. if that is what you want the interior to be like.. "make it so". I do like Doug's idea of "soft walls".. don't think it would really be that hard to do.

Welcome.  I partly agree with this, I made a similar suggestion a few years ago based on the wet bath we had in our Coleman popup.  I wouldn't want to get rid of the bathroom, but the space could be greatly openend up if the hard walls of the bathroom only extended up to just above the toilet seat height.  Above that a wrap-around shower curtain would work for showers and for "privacy" (certainly no less privacy than the existing door).  The soft curtain on 3 sides would allow for much more elbow room than the 4 hard walls.  All 4 sides were shower curtain in our popup and I really liked it.  Roll the curtain up to the ceiling (what we did in our popup) and the space opens up between uses.  You could put a hard top over the hard walls, this was standard in our popup but I eventually ripped that lid off because it got in the way.  You couldn't use it as a shelf because then you had to move the stuff each time you wanted to use the bathroom.  Maybe a roll-top would work, like a roll-top writing desk.