Fastest way to get above the 5th fret is to play the melodies you already know an octave higher than usual. You can also start learning your up-the-neck chords, at least in open G and double C tuning.

Find a fiddler to play with. Explore all the different ways to get up-beat notes - pull-offs, slides, drop-thumb etc. - and all the different variations of rhythm - bum-a-diddy, diddy-bum, rack-aracka, up-strokes, silent strokes, chucks and clucks (and how to use these tastefully). Learn the so-called Galax lick. Listen to a lot of different players in different styles, explore variations in sound playing from the bridge to the fingerboard.

There's plenty of fun to be had without ever going above the fifth fret.

Musicianship is as much about doing the basics better as it is about doing ‘more’.

Work on tone, accuracy, timing, phrasing and economy of movement. This isn’t a ‘stage’ we complete and move on from. This is a lifelong engagement. There is always scope for improvement.

Gradually extending our use of the fingerboard occurs naturally as we attempt tunes that include those notes, typically starting by adding the 1st string 7th fret.

But a left hand that is all over the higher frets without constant, close attendance to those basics is simply an illusion of advancement.

Learn Blackberry Blossom. It will get you up the neck a bit and work on usng your thumb for melody notes. It’’s not all that hard, really. When you have learned it, you’ll be on your way to working up the neck and with your thumb dropping as needed instead of in a pattern. Working out a tune is more fun than practice exercises—and brings you to the same end.

Bump dit ty is not quite the right way to see it. It is a four count so I would recommend thinking bump ah dit ty. The ah is a pull off on the 1st string, for starters. It is a Paradiddle, RLRR. Bump=R Ah=L Dit=L Ty=L. I would also highly recommend Brad Leftwich's book on Round Peak Banjo. It will push you into new abilities and possible new directions even if you don't particularly want to sound like that.
Hope this helps even tho it is not about up the neck.