Maybe I just need to not be lazy about it, and set the ISO when I change from indoors to outdoors.
I did a shoot a day earlier completely inside, in semi-stable lighting conditions, and I had it set for 200, using ETTL. The shots came out fine.
Thanks for the response.
The one thing I have never attempted was Auto ISO when using flash. Just never felt comfortable with it. Indoors I typically have all the settings on manual, flash on ETTL or Manual. Outdoors typically on Av. However I have not put the flash on the R yet.