Like you said, it's extremely hypothetical.
You don't know what grades you'll get this year—or next Fall.
But let's say, for argument's sake, you do. The trade-off then is (the possibility of) a slightly higher GPA vs. applying early. It's probably a wash. Going complete early gives you more consideration and the most chance at the few spots that are truly competitive in a law school class. A higher GPA always helps in that it can move you from the maybe to yes category, but you're again assuming a lot about your grades.
A middle of the road option would be simply to apply as early as possible and then update schools after your Fall semester grades are in. It's unlikely that any of your target schools will have accepted or denied you before then.
If it were me, I'd apply early and hope for good grades next Fall.