Whilst it's not normal to break a string on a bass guitar, obviously it can happen. A few days with one less string won't hurt the bass. Keep things as they are.

A more important factor - and it's not the first time it's cropped up - is how so many can't tune without resorting to a tuner. Yes, it's accurate (but not in your case!), and it's quiet (not when amateurs do it!), but there's absolutely nothing wrong with being able to tune it properly yourself. That way, you'll listen to the sounds, and making a mistake like you did will be a thing of the past.

A couple of ways - fifth fret on a lower string will be the same note as the next string open. 5th fret harmonic is the same note on one string as 7th fret harmonic on the next higher. So once one string is at the reference point you need, the others can be tuned perfectly, assuming the bass is intonated properly.

Whilst it's not normal to break a string on a guitar, obviously it can happen. A few days with one less string won't hurt the guitar. Keep things as they are.

A more important factor - and it's not the first time it's cropped up - is how so many can't tune without resorting to a tuner. Yes, it's accurate (but not in your case!), and it's quiet (not when amateurs do it!), but there's absolutely nothing wrong with being able to tune it properly yourself. That way, you'll listen to the sounds, and making a mistake like you did will be a thing of the past.

A couple of ways - fifth fret on a lower string will be the same note as the next string open. 5th fret harmonic is the same note on one string as 7th fret harmonic on the next higher. So once one string is at the reference point you need, the others can be tuned perfectly, assuming the guitar is intonated properly. It doesn't work between 2nd and 3rd strings, but the 7th fret harmonic on fat E is the same pitch as 2nd string open. Sounds complicated, but once you get used to it, it's as quick as with a tuner, honest!