To the OP: I'm an engineer and not a banker, but I am here for work-related reasons. My wife works in the field of education and is a local who was born and raised here. We have been in HK for nearly a decade.
A visitor has a very different experience in a place than a resident. Unfortunately, short of actually living here for a month or at least several weeks, I don't think that there's any way for you to really gauge what moving to HK would be like for you.
Money does help as it allows you to dip into the "real HK" or immerse yourself in it to whatever degree you choose while retaining the ability to maintain at least some aspects of the higher standard of living to which you are likely accustomed.
Bumming it can be fun when it's a conscious choice but if extreme frugality is forced upon you, it's unlikely to be fun.
With a very few exceptions and unless you have an entrepreneurial fire in your belly (and a visa and start-up capital that would allow you to explore the option of opening some sort of independent teaching centre), I would imagine that teaching in HK would be a hard slog for you.