My youngest daughter and I did a Rt66 trip from Springfield IL to Amarillo TX and back (we live near peoria il) in early July this year. Used our 34 foot Class C only, no toad. Was a fun trip. Some parts we just popped on the interstate. As mentioned, we had several published books about 66 trips. We made detours, such as Laura Ingalls Wilder home in Mansfield MO, where she lived 63 years and wrote all the Little House books.
Our favorite stop was Big Texan steak house on 66 in Amarillo. We ate there twice! We also did Palo Duro Canyon State park south of Amarillo.
In 2017, we did 66 from Amarillo to Kingman AZ. Never did the whole trip, just parts over the years.
Point is, our 33/34 foot C did fine...tiring after while to pack up each day (not a big issue, just when you are the only one doing it because wife stayed home to work!). I planned 80% + of all stops to avoid issues. Parking was my main concern but ended up with no issues.
Stop at the National Rt66 Museum in ELK CITY, OK. It was worth the stop!