Honey, the mere fact that you have an employer who is willing to [1] relocate you, [2] pay for your expenses, [3] provide monthly global travel, and all of this in [4] a top tier Chinese city is fantastic. Yet, you question it. Are you out of your mind?
Come to China, and enjoy the adventure. Yes things will be different. You cannot make apple to apple comparisons. So throw away your ideas that you will act and behave like you do in Europe. It just will not happen.
Your salary is equivalent to that of well-paid manager. And you are what? A female under 30 years old. Do you have any idea how great you have it?

Your assumptions about the tax you will pay are wrong. Your assumptions of your lifestyle is wrong. Your thoughts about who you are and what you can provide is ego-inflated.
You like to go out and party, good for you. But do not expect Western-style parties. They drink baijiu here. It's 53%. It cleans grease off engine blocks and then you can use it in the automobile engine. If you think you might have some fun doing drugs...well that is not going to happen. Drugs are terribly illegal. You have two marijuana cigarettes and you can get arrested for distribution. Which is a DEATH sentence. Though you would get death plus three years = three years of mandatory organ harvesting before they shoot you and bill your family for the bullet.
If you accept the job transfer, be advised that you will be expected to do your job, AND integrate into the society. Most can't. You will arrive single, so you will not have a support network. This might serious affect your longevity, even in a Western-influenced Chinese city. Most single Americans (I don't know about Brits) only last for two months before they high tail it home. Plan accordingly.
Are you ready to learn Chinese? You had better. I've been living in China for fifteen years now, and my language skills are on par with my little dogs.
So to answer your question. You will have MORE than enough to live on, and you will be able to save as well. I would advise you frequenting Western establishments and eat local. A Burger King hamburger will run you 50 RMB, but if you eat local Chinese dim sum, noodles or dumplings, you will only pay 15 RMB. If I moved to London, would eat fish & chips instead of going to PizzaHut every day.
OK. Enough of the hard sell. Let me tell you this straight. You have an excellent opportunity. I would advise you take it. If you fail, or fall flat on your face, at least you can say you gave it your best. If, on the other hand, you thrive, than that is fantastic, and you will look back and say the this was the best decision in your life.
Finally, NEVER, and I do mean NEVER make decisions only upon salary. You will hurt yourself in ways beyond your comprehension. Hon, sincerely wish you the best. Good luck.