I'd rather say to go back to your old ideas then wait for new ones, because it'll probably be a little easier to work out the plot and stuff instead of trying to make an entirely new story where you need to do the chapters again and do other stuff that's important, including the characters, considering they're a total pain to figure out how they'll look like, what mask they wear, etc. ><
But still, when doing new ideas it gets hard to have one idea and then think of a new one, since it'll keep on going until finally you have too much stuff. Which happens to me all the time. But either way, if you have an idea you might want to finish old ideas and start to do new ideas after old junk is finally done, if you know what I mean.
Keep in mind that this is just some advice. Do whatever is better for you and doesn't get in the way of other things, 92.
EDIT: Also, Happy New Year.