What Andrew said, it helps a ton! But in addition, keep working on the song with the obnoxious chord fingerings. Don’t hurt yourself though! I can reach from fret 5 to 12 on a soprano now if its on 2 adjacent strings or i’m chording something in a 3 finger stair step pattern with skipped frets, and just need my pinky to dink around further. (Sorry my theory isn’t to par to tell you in a way that makes more sense.)
I found my thumb position matters more when you’re at your limit too. If I was trying to get a really bad one I had to shift my thumb towards my pinky more and angle my wrist a bit differently.
I am working on Prelude from the cello suites from John King’s ukulele book and I still can’t get those fingerings without playing a couple bars then just stopping. PURE TORTURE for short fingers! I’m supposed to pretty much let each note keep ringing and that song’s like playing ukulele Twister…… Prelude sounds so amazing on uke though I’m determined to play it! I just keep cursing while trying lol.