Except for last summer, when medical issues stopped me from riding completely, I have ridden my Deuce (2002 Harley) every month since I bought it. That means winter time too, and it gets mighty cold up here in these mountains. So I have started that bike, which is fuel injected, every month for years now. Same thing with my wife's Sportster (2005, carburated) While I've never bothered to see what the temperature was when I started them but I can assure you its been far far below freezing and probably below zero more than one time.
But I have to ask you something, why do you think it would be any harder to start a 4-cylinder Honda than it would be to start any carburated car? They start at below Zero (f.) temperatures all the time. The only vehicle that I have that is hard (read nearly impossible) to start without outside heat is my diesel truck. With it sometime, in very low temperatures (< -20 f.), the truck simply will not start at all. With two batteries it cranks like hell, but all you get out of it is unburnt diesel fuel spewing out the exhaust in the form of vapor. Very stinky.