Drive from Shizuoka to Nagoya in golden week

I will travel to Japan during April 15 to April 30, 2019. I made a bit mistake because I didn't know that this year golden week will start on April 27. I rent a car for this trip and I will return it at Nagoya on April 27.

I will drive from Shizuoka to Nagoya on that day and I just can't leave before noon. My question is how bad the traffic will be on the express way from Shizuoka to Nagoya in the afternoon time? Or is it better to avoid express way?

Thank you.

The main road(本線 honsen) on the expressway can run without problems, if no big car accident happend.
However, SA/PAs will be full until night, means also your car not be hard to enter,
https://globalsapa.c-nexco.co.jp/en/search/map/
https://www.shimizusouichi.com/wp-content/uploads/2015/11/003141_photo...
https://www.shimizusouichi.com/wp-content/uploads/2015/11/003141_photo...
especially for toilet(トイレ restroom) break possible or not is the biggest problem.
Even if you can park, but waiting line of ladies toilet will be very long, over 30min is not a lie.
https://twitter.com/c_k6h6j/status/859592849750335492/photo/1

If go on expressway, watch and listen carefully traffic info boards
https://www.c-nexco.co.jp/jam/cause/measure10.html
and "highway radio(ハイウェイラジオ AM 1620KHz, find car-navi button）", only Japanese, though.
https://www.clarion.com/jp/ja/manuals/NXV977D/images/17_0167.png
交通情報 koutsuu jouhou = traffic infomation
渋滞 juutai = traffic jam(in expressway under 30km/h cases are called)
事故 jiko = accident (car's mainly, including break down, and other rare cases)
分 hun/pun = min (30分 = 30min)

So, water intake should be modest and should also buy a little more foods. (out fr trunk)
Fuel(Electric) charge full before entering expressway is the best way, bc it may get stuck very long time.

Thank you so much Gr-A!!!