I don't know the exact height of the MD-80 bins, but I have a nine inch thick hardshell that doesn't leave much wiggle room in those bins, so I would guess that the bins are about ten inches tall.

Bad news for you.

Your bag is too large to be a permitted carryon if it exceeds 45 inches in total dimension (AA's permitted dimension, consisting of length plus width plus depth), so anytime your bag exceeds 10 inches thick, it isn't a permitted carryon. If it is about 11 inches before packing, then you're already at 46 total inches.

IMO, a similar bag not designed for an "over-packer" is what you need.

Something that knows how to stay within the 45 inch rule AND that knows how to stay svelte enough to fit in those stupid80 bins.