Along the same lines as Mr H suggested, I'd book whatever you can get now that will get you to CDG. QR is unpredictable - apparently they have had to take some of their A350's out of service because of issues with their paint (of all things). That has exaccerbated their well known unpredictability and lak of a pattern when it comes to the release of award seats. Certainly you should book what you can now, then you can change if more suitable availability is released. All their planes should be back in service well before you travel next April but who knows for sure whether they will be back flying all their usual routes or not?Brains trust I have seem to have a problem,,booked my seats to Doha waiting for connecting flight to paris(going to Anzac Day at villes bretonoux) as they release them.They have not released business class tickets for 3 weeks prior to 20th April but have release Europe connectors for May am I in trouble or will they release some later on.
I think your best bet would be to try and book DOH to LHR or HEL with QR. From LHR you could transit to CDG with BA, and from HEL there's plenty of AY flights to CDG. Both BA and AY usually have good award availability on LHR - CDG and HEL - CDG but I'd prefer AY as their taxes are minimal. QR does fly to a lot of other European cities you could possibly transit through to CDG, but most aren't serviced by OW airlines so you wouldn't be able to include them in your OWA.