Tuning question?...

Hello all, I am a newbie to Uke. I have a concert scale Little Gem....I also have 2 banjos....both 5 strings. What I would like to do is tune my older 5 string to a low g Uke tuning. So now I’m wondering what to do with the 5th string...do I leave it high G or some other key. My inclination is make it a C. Thoughts....

As both a ukulele and banjo player I'd suggest removing the 5th string completely, also be prepared to choose some compromise tuning for the long neck, then fit a capo to bring the instrument up to pitch, else you're likely to run into all sorts of tension problems