Before the baby, we were approx 6km from my workplace. I biked all summer and other nice days. Almost all of the way was slightly downhill so I didn't have to sweat much to get to work and I biked with dress pants, shirts and dress shoes. It was that easy.

Coming back from work was a different story, the bike time doubled as I had to go uphill all the way. I felt great.
After the baby, we moved further at a bigger place, have to transport the baby around, the bike's been freezing now.
If I had the choice and was almost the same distance, I would bike again.