Driving from Narita to the Romantic road

I have planned to drive from Narita making a first stop in Shiobara spend a night there then make my way down to Nikko spending a night in Lake Chuzenji.
The third night will be to Takaragawa Osenkaku then drive to Karuiawa.
I don not know if there is a nice place near Karuizawa.
Does one need to book a place to stay or one can just walk in?
My 5th day will be around the Five lakes in Fuji area spend a night there.
Then drive back to Tokyo Shinjuku.
I have all the names of the hotels but could someone
advice if the planned is feasible for 5 days?
I also need a recommendation for a hotel near Karuizawa.
Thank you
Parry

Does one need to book a place to stay or one can just walk in?

Walk in is very unusual and not recommended, except in case of a business hotel.

I have all the names of the hotels but could someone advice if the planned is feasible for 5 days?

Yes, it is feasible. Quite a lot of driving, but feasible.

Most challenging will be finding your way through the expressway jungle of Tokyo on your drive from Narita to Shiobara. Try to study Tokyo's expressway network in advance.

Thank you Uji,
Your answers helped a lot.

Just for the records if anyone is driving this route,
There is a onsen town called `Hoshino' it is by the foot of Mount Asama and by the river.
My Japenese friend has recommended me to stay here on my way down from Takaragawa to The Five lakes of Fuji.

Parry

I've just got back from my driving trip from Narita to Shiobara-Nikko-Lake Chuzenji- Takarakawa-Karuizawa-lake Kawaguchigo-Tokyo.
The route is so beautiful with full colours of Autumn leaves.
The temperature vary from -6C to 16 C.
My only difficulties are the two things:
The most beautiful route I would recommend is the Nichien-momiji line. There are more than 40 curves up and down the mountain the total drive was around 22 km.
But it took me 4 hours to complete as I stopped and took so many photographs - you can imagine how beautiful it was !! The only difficulty is that there were no English sign of this route (Nichen-Momiji line) I have to ask around and there were hardly anyone who can explain to me in English, I got by anyway buy following the Hunter ski ropeway sign.
The other place that I drove pass and missed was the
Fukiware Falls to which was one of my highlights.
I did not see any signs....!!
The rest of the journey was lovely, the people are very graceful the driving was not as difficult as expected as I have an English map and a GPS to follow.
I will surely drive again in Japan, as you can see many things you cannot see on the train.
Please recommend any more trails that I need to see?
Maybe for the Cherry Blossom time....
Thank you Japan, I really adore you ....
Parry

Thank you for your feedback. It is good to hear that you had a nice time.

Driving is nice in most areas of rural Japan. Some of my favorites are the Yamanami Highway in Kyushu around Beppu, Yufin, Kurokawa and Aso. This is very nice if you like hot springs.

Also one of my favorites is the Hachimantai area around Nyuto Onsen and Tamagawa Onsen. It is especially nice in autumn. Again, especially good if you like hot springs.