I have no real data, but anecdotally a large number of my peer group (tech folks in NYC) fled the NY Metro Area in March. Those who had (not at-risk) family nearby stayed with family, while others (like myself and my partner) are quarantined in Airbnbs in more remote areas (although still close to a functioning medical system).

It's costing us an arm and a leg, but we've been very fortunate in that we can afford it. We normally live in a high-traffic apartment building with multiple dogs that require walks, so exposure seemed likely (and indeed a doorman later tested positive).