I'm avid cyclist, possibly a bit too avid. And even I do not bike 'year round' in the Netherlands. Falling can be a real risk, cycling in traffic can add to that risk. Snow and ice are an easy way to break a bone when you're on a bicycle.

Scandinavia and the Netherlands have the added advantage over 'most of the developed world' of having a lot of bicylce paths, NL being as flat as a pancake helps even more (though it can be very windy here).

Age, terrain, weather (temp, wind, precipitation), physical condition of the rider, traffic safety and so on are all contributing factors in whether or not you should take the bike or rather not. But under normal conditions in a place where cycling is safe and the weather is ok'ish 5 miles is biking distance.