Not giant, but round head here, I have the IMS 7.0 medium helmet.
Came across the new True Dynamic 9 Pro at Sportchek. Somewhat unique concept, as there seems to be no front-to-back nor width adjustment of the outer shell, just different pad thicknesses of the "floating" inner Mips liner.
Size-wise, for width, I couldn't even get a medium size past my temples, but the large was just a little snug using the 6mm Fitpads and with glasses on. A bit too much play front and back on the large with the 10mm occipital Fitpad. Didn't want to rip open the extra bag of Fitpads to try, as I'm not in the hunt for a new bucket, but using the 2mm side Fitpads and 15mm on the rear, this could be a viable alternative for me. Worth trying for Stewie Griffin types.