Umm, the conference room at the rear does have small bunks for four people... (Or did, until those were recycled as Defiant
But yeah, smoothing in the same style as the change from the standard VOY "Type 12" speedboat to the roughly similar shuttle flown by Admiral Janeway in the finale. Possibly a slight change in size. For some reason, TNG movie shuttles have been larger than the original TNG series ones - Starfleet might do the same with their runabouts, for unknown reasons.
Older runabout types would also be fun to visualize. Something fitting the TNG Type 7 shuttle style for mid-24th century (possibly the big warpshuttle in "Skin of Evil" was actually an older runabout?). A TOS movie design - I have no real ideas for this.
And a TOS design... The craft seen in "Way to Eden" would be a very nice TOS runabout, or perhaps slightly pre-TOS so that civilians have now acquired these surplus models. Older, clumsier tech, so it's bigger and has real trouble landing (but perhaps it can still manage?).