Kamikochi in golden week

Our family(2 adlults and a 6ys old boy) is thinking of going to Kamikochi during the golden week holidays.
We are planning to drive rather than taking train.
Here is our itienary
Day 1 : Leave Tokyo early morning on 29th April and reach Hirayu no Mori at around 2pm.Enjoy the bath and stay at Hirayu no mori.
Day 2 : Leave early morning from Hirayu no mori to Kamikochi( Take the bus from the hirayu Parking area). Spend the day and night kamikochi
Day 3 :Spend the morning at kamikochi and leave for Hirayu no Morri in the afternoon. Again enjoy some baths and stay at Hirayu no Mori.
Day 4: Leave early for Takayama. Spend the day at Takayama. Either stay in Takayama
Day 5: Spend the morning again in Takayama and leave for Tokyo in the afternoon.

1)Any comments/suggestion about this plan?
2)Instead of going from Sawando we are thinking of going from Hirayu so that we can enjoy the onsen there. Is that ok?
3) How will be the weather in Kamikochi and Takayama during Golden Week? (Are tire chains required?)
4) We expect traffic jams due to peak season but apart from that is there anything we need to consider?

Any advise/suggestion is really appreciated. Thanks.

I feel the driving part on day 1 (4.5hrs) and last day (5.5hrs) is really long. Maybe u can consider taking the bus from Tokyo to Matsumoto and rent a car from there. The car will allow u to visit say shin hotaka near hirayu and shirawakago near takayama.

Thank you for the answer. I ahve been doing some research on the net. I think we will drive from Tokyo although it's a long drive. Because the idea is to drive.

Day 1 : Tokyo-Hirayu no mori
Day 2: Hirayuno Mori to Hida-Takayama
Day 3 Kamikochi
Day 4 Kamikochi to Matsumoto
Day 5 Matsumoto to Tokyo
is the new plan.

Any suggestions? Especially can we get any input from you Mr. Uji? Thanks in advance.

How will be the weather in Kamikochi and Takayama during Golden Week? (Are tire chains required?)

Usually there is no more snow, even in Hirayu, and chains or snow tires are not required.

The real bulk of the Golden Week does not start until May 3, so I don't think that traffic jams will be a major problem. And on May 3 you are traveling in the opposite direction of the rush.

I agree that a lot of driving is involved, but if that is waht you are looking for, I think it looks like an enjoyable itinerary.