The cacti & succulents forum is probably more appropriate, not that this is the wrong forum, but it would be better to ask advice somewhere with lots of people that know cacti and succulents very well. Also, if you post there, ask about pruning it. I believe it is possible and would solve your "hanging over the side" thing. If it is possible maybe you can train it upright into tree form afterwards?

I have one that looked just like this.
I cut off the top of it, leaving some stem, and potted it up.
It rooted and looks beautiful now.
I also left the rest of the plant in it's pot and it's sprouting a new plant.
I didn't know if either of these things would work....but they did !

I would put it in a deep container and bury that stem. Or cut it off and put it in soil

Thanks for the advice, much appreciated!