Google Maps says its 1’333km flying to our first destination:
If I count 40 days on the bicycle, at 60km per day, we can do up to 2’400km on the road. This is 180% of the direct distance. Based on past experiences it is a fairly short estimation. For instance for the same 1’333km of straight route, the algorithm calculates walking for 1’607km, driving for 1’806km and bicycling to the Spanish border (there is no suggestions for Portugal yet) for 1’603km. Hopefully the heat, wind, legs and brain allow to do it without stress.
For the note, on our last 3-week trip (Basel CH, Leiden NL, Bremen DE) we did 1’800km, but the direct path shows… 876km, so we did 205% of the direct distance!