Be very careful about that decision. If you're prepared to drop that kind of money on a lens AND body, then you are much better off spending it on a killer lens instead IMO. I 100% understand your pain and that this puts off getting a full frame for longer then you'd like, but when you find yourself in a low-light situation, trying to freeze action, you're going to be kicking yourself that you don't have that f2.8 (plus, don't even get me started about how much sharper that lens is!). It's your money, your decision, and perhaps you don't shoot any low-light action, but definitely try and separate the short term value (lens and body) and consider the long term investment (killer lens and hold off on the body) before purchasing. Again, this is 100% your decision so do what you will, I've just seen too many people blow their cash on high end bodies and compromised on glass. If you can afford perfection, why not get perfection?
That's on my list of quotes I have on my notes app - "Buy once. Buy right."
Currently I do very little low light work. Hopefully over summer as the weather gets better and I start taking more photos, I will get a better idea of my true needs. Buying expensive things is always a pain as you spend SO much time weighing the pros and cons of all the various options in the hope you don't make a mistake.