I did the 830 mile (1,336km) slog back home from Reims last year.
This year I'm heading out early on 6th August and joining the Frolic at Dijon.
Boosting home on Sat 19th August:
Pau to Calais, 670 miles (1,080km) / 10 hours
****crossing****
Folkstone to Home, 630 miles (1,015km) / 11 hours
Not sure where (if???) to split that.
French side would minimise impact of any pre Tunnel delays...