I make 1 hour connections from international arrivals to departure from another terminal rather routinely at ORD, and this is at various times of the day. As long as no checked-in luggage is involved, I generally have no issue regardless of time of day as long as my flight arrives close to on time. However, if there are delays on departure to ORD or holds/gate issues on arrival at ORD, then all bets are off. If there is checked luggage involved, that can really wreck plans.