8 day road trip in Sept.

Norway is a huge place to travel around, so you will have to be prepared for long drives if you want to go further afield in your own vehicle, but you do get the freedom of travelling where and when you want to. However, Norway has an excellent state railway (NSB), and the journey from Oslo to Bergen, crossing the Hardangervidda, is considered to be one of the most spectacular in the world. There's also an especially scenic side route between Myrdal and Flåm, in the heart of the mountains.

Bergen is a lovely city, so you should certainly visit. It has a fantastic seafood market on the quayside, and lots of history. It might be an idea to hire a car here, rather than in Oslo, to explore further afield, either into the mountains or out to the islands. Or you can find a boat cruise to Hardangerfjord or Sognefjord.

Weather in September is generally pretty good in these areas, I've done some fantastic walking between tourist huts on the Hardangervidda at this time of year, but you should be aware that Bergen can be the wettest place in the world with rain almost every other day.

Visit Norway has a great website to give you some ideas. Have a look at it and identify things that you'd really like to do, as a family or individually, then start to put a plan together for your days. Work out if you can reach places in time, bearing in mind that you will find little open on Sundays, using rail/bus timetables, then look for accommodation that meets your needs. Everything in Norway is expensive, so it might be an idea to compare prices in NOK to work out what seems reasonable, rather than try to translate costs back into EUR/USD or whichever currency you're used to.

Early autumn will be very scenic almost whereever you end up. As for wooden churches- do you mean stave churches in particular, or any kind of wooden church? As for stave churches I reccomend Eidsborg, which has a small church that still sees use and a museum for western Telemark. A somewhat pricey but rather attractive itinerary that might get you there starts in Skien (my hometown and a town LP brushes off with almost a "mostly harmless"), takes the canal boat up the Telemark canal with lots of interesting locks, small passages and large nature to Dalen. This takes a full day. Spend the night there, possibly at the old era hotel (a taste of the 1910's)- very good restaurant and interesting rooms but the price reflects the class, alternatively rest at a B'nB or rent a cabin at the local campsite. The hotel owns one of the canal boats, you can order fare+dining+room combos. The morning after you can take a bus up to Eidsborg, spend a few hours there and take a bus from Eidsborg to Seljord, and from there either back to Skien or back to Oslo. You can also jump on the Haukeliekspressen coach westwards to Bergen, Odda or Hagesund. If you take the Oslo bus and are not sated with stave churches you'll pass the large Heddal stave church on the way, jump off the bus there and take the next one after some sightseeing. You'll have to research the timetables yourselves, as they are revised at least once, often twice a year.

I have a few other reccommendations as well 'near' Heddal (a large hour drive away) if you choose to go by car: Gaustatoppen mountain peak from which, given a clear day in all directions, you can see 1/6th of Norway. It can both be hiked and reached by a undreground cable train system. Below the peak and a bit to the south you'll find Tuddal høyfjellshotell which has a very good kitchen. Northwards you'll drive down to Rjukan where you'll find Vemork and the industrisal workers museum and can get a bit into ww2 with the heavy water sabotage missions. A bit further and you reach lake Møsvatn, where a ferry runs to the staffed lodge Mogen from where you can have several hikes of varying difficulty, buy a fishing license and give the ol' rod a whip and of course stay for the food- the lodge was declared the best culinary lodge this year. Check timetables and book rooms when the trip approaches, a few weeks prior at least- this could save you a bit expences.