That is around 30 minutes of leisure pace kicking, 20 minutes if you are in a hurry. The key is to change kicking leg every 5-10 kicks.

I drive 200mm wheel scooter, so one kick sends you a long way, if you are on a good and plain pavement.

It's feasible, with some training. The first time I have done this, I thought my legs were going to fall off the next day - kick scooter riding is more tiring than riding a bike. After about a week, I was able to do a 6 km commute on a scooter without a problem.