So, checked the gauge again after letting the piece sit a few days, and it is too many stitches/4 inches, even with a #6US.
So instead of going to a 7 first, I will try two things.
First, switching to an Addi Turbo...let's see how the slickness of this might or might not make the stitches looser.
If not, then I will try to knit inside-outish. The thinking with that is having the floats on the OUTSIDE of the work might make them a skosh longer, loosening up my color-work stitches.
Only if both of those don't work will I resort to move up to a #7.
Now, if only I could kick my kids out and shut the parrot up.