I think uninterrupted walking is the best, so IF you insist in starting at SJPdP and ending in SdC, then I’d advocate two long walking sections rather than multiple jumps in your itinerary. Only you can judge your walking speed and daily desired distance, so you’ll need to think about those factors when deciding your route. So SJPdP to Burgos (2 weeks) and then Sarria to SdC (1 week) MAY work if your walking allows that.
As for the Pyrenees? Nice, but I think overrated (start the avalanche of criticism!!!
) for the effort folks go through to get to SJPdP. It’s a nice 1 or 2 day walk, but so are other spectacular portions of the CF! I think starting three weeks out from SdC and walking continuously is still the best way.