For us, that would be too much food. we normally do a QS or kiosk at lunch and a signature at dinner.
If you space them out, it is doable.
But, you will also spend a significant amount of your park time at these meals.
I wouldn’t do them both in one day. The only time we do two TS in one day is if one of them is breakfast. Since you’re already doing Whispering Canyon I say cancel 50s Prime Time. Woodys Lunchbox at HS is my family’s
Favorite QS, if you haven’t tried it yet I’d recommend it.