How many has that actually happened to? Like you applied for a job, and they said, "nah, you're that weird school up in Idaho."
I think that concern is WAY overblown and is just pride. It's not that your degree is actually devalued, but that you can't stand having those Idahoans associated with you. It's quite elitist.
Other mega universities have main campuses and satellite campuses and it all works out just fine.