When my D studied abroad, some of her cohort were from Whitman. She got on great with them and felt she would have enjoyed attending there.
I think the OP’s child is aware that these colleges are off the beaten path. Location doesn’t seem to be the issue. OP’s child could consider freshman retention rates. Grinnell’s appears to be 81%, while Whitman’s appears to be 89%, according to college factual. That means that more students return to Whitman for their sophomore year than do students at Grinnell. Could be worth considering.