Since you're hesitating, you might want to consider getting a take-down bow where you can add additional limbs later on.
I assume you feel very comfortable with your 50# bow. Hopefully, what this means is that you can come to full draw and hold and then fire the arrow when you're ready, and not just because you can't hold it there any longer. And do this a number of times in a row.
If you feel that comfortable, then you could probably get used to either a 55# or 60# bow. The difference is that you will be able to shoot the 55# bow more times in a row, under control, than you will the 60# bow.
Keep in mind that if you're cold and miserable and sleepy and your muscles are cramped and this is your only chance in a five day hunt to shoot an arrow at a big elk, and you haven't shot any practice arrows, you don't want to be shooting a bow that you can barely control when you're warm and happy and shooting at targets.