I guaranty that the Republican Party of Iowa did not knowingly give Quinnipiac lists of caucus attendees.
Candidates have such lists, but are prohibited from sharing them, and there’s probably too much downside to cheat. There’s a felony conviction for prohibited campaign practices in Iowa news right now.
Then the question remains: Where did the list come from?
Did Quinnipiac develop it on there own, and how?
And really, how does one really poll a caucus state?