Northwestern has programs for K-level. Distance might be a problem, though, and I'm not sure that I'd try online courses for such a young child. They do have online courses, though.
Your DS sounds like a normal 5-year-old boy to me.
Is he on the young end of his grade? We ran into a teacher or two who pointed out DD's (now 8) immaturity (lots of asychrony) in younger pre-K and even occasionally K...well, she IS younger. She "called out," too, when younger. Doesn't seem to be an issue now, but it did cause me to question whether I'd be battling this for years to come (many summer birthdays are "held-back" in my area). Still, I could not fathom holding her back simply because she was young (she was also very academically advanced), so I didn't. Turns out that was ABSOLUTELY the right choice.
I would stick with "live courses" for a younger child. Do you have any colleges within driving distance that might have "summer youth college classes" or something similar? Also, my DC have benefited from some classes that were not necessarily aimed at G&T, but were of high-interest to bright, curious kids (science, chess, cultures around the world, etc.). These, too, can be great sources of enrichment.
Best wishes and let us know how it is going!
