I just finished three cable hats
The pattern I used was also 80stitches around, but it was a b it different in that you alternated cables with stockinette (6 st cable, 2 purls, 6 sts stockinette, 2 purls, etc). The pattern called for decreasing 8 sts every other row, starting with the stockinette portions, then the purl stitches, then the cable parts were decreased last.
I’d probably put in a lifeline before you start, just in case it looks wonky…then decide which part you want to decrease first, the cables or the purls in between. For example if you decide purls, then maybe start by dong P2tog, k6 all the way around, then knit a row straight. Then decide how you want to decrease the cables…such as, I’d probably decrease every other cable (ssk, k2, k2tog) or something like that.
Eventually you’ll want to switch to decreasing every row instead of every other (usually I do this halfway through the decreases).
LMK if that made any sense