Just updating this threat just in case someone has the same situation in the future and comes across it. I was able to make it to my home country for the funerals but this was far to be straightforward, I had to depart with my home country's passport and return with the Canadian passport.
First, it was possible to apply for the Canadian passport without the original citizenship, something I found about only after contacting the nearest Canadian embassy from my country when exploring options to return if I had to travel without. So I just went to the Passport Canada office in Kitchener, they asked to provided a receipt proving that I actually submitted an application to replace my original citizenship certificate. Luckily I had it in my computer on that day and so went out to print it and submit the application. They also mentioned that I could only get a 2-year passport, and then I could apply for the 5-year or 10-year one once I have my original citizenship certificate.
Now it was an express application on Monday and I was supposed to pick it up on Wednesday morning for a flight late in the afternoon first to the US, then a late correspondence to my country. On Tuesday they called my guarantor and references and I thought all was good (had to replace a reference by the way as the one I included was abroad and unreachable). Then they call me to say for my application they need to receive a confirmation from the IRCC but have not been able to reach them so instead of picking up in the morning it would be probably at end of the day (4pm).
I still went early to Kitchener to wait but to no avail, no IRCC confirmation and Passport Canada could not reach them. Once again I was confronted to IRCC wall of silence. I was informed that I will not be able to get the passport that day. I decided to leave anyway and confirmed with them that my wife could pick up the passport if/when ready.
I then drove from Kitchener to Buffalo NY which was my plan B with the goal to cross the boarder with my country of birth passport which had a US visa. New hiccup there as I was brought into a room for interview, and told that although I had a US visa until 2028, my passport was expiring in two months something that I completely overlooked. US requires a passport with at least 6 months validity to enter. The border agent said I can exit Canada without entering the US and as such I will not be permitted entry, even after I explained to him that it was to board a flight in New York to return home for funerals.
As we were talking he then realized I was a Canadian citizen. He said I should have brought this up to save time instead of my other passport. I only had a copy of my citizenship certificate with me and based on that I was allowed entry to the US within 5mn!
Drove from the border to Buffalo airport but it was too late to catch up my flight for New York so had to reschedule for the next day. Eventually found out there were more flights from Rochester to the specific airport I was going to (Newark) so bought a ticket from Rochester online and booked a hotel room in Rochester just opposite to the airport for the night. Rochester is about 1 hour drive from Buffalo and I was getting there around 11PM.
Next morning I went to a UPS store near my hotel in Rochester to send the receipt for passport pickup to my wife (didn't have the time to do that the day before as I left Kitchener around 4PM) and then went to take my flight to Newark just after noon. Trips to Newark, and from Newark to my country didn't have any surprises (was already tired at this point lol).
Attended the funerals on Saturday that week all went well (figuratively) but now the issue was to return to Canada. Saw my brothers and sisters leaving one after the other to the US or Europe while I was stuck with no way of leaving. Again my country of birth passport was expiring in two months so I would not have been allowed on board on any flight to the US. I did apply for a new passport there but it may have taken even longer while I only had a 5 day bereavement leave from my workplace.
Finally, on the Wednesday of the following week, my wife finally received the call that the passport was ready for pickup in Kitchener. She went to pick it up and send it to me by DHL. Was able to receive it the next Monday at 8AM, and at 12PM I was in a flight back to the US. Return with my Canadian passport which I first received in a DHL office in a city in West Africa was a breeze and the US border officer didn't ask the usual questions I was used to whenever I had to enter to the US on my previous passport.
I landed in Washington DC, had to take a Uber to go to a different airport to take another flight to Rochester NY to pick up my car. It was already 11PM when I got to Rochester Airport. I didn't want to stay another night in the US so I decided to drive back right away. My Rogers phone chose this time to have data issues so I couldn't use the GPS, I have probably wasted an hour or more just because I didn't take the right highways or exit, eventually as I got close to Buffalo the data started to work again so was able to use Waze to find my way. Crossed the border through the Peace Bridge and was home in Mississauga around 4AM.
It was quite a journey at the end it was worth it at least as far as I am concerned. Three days after I returned home, after ignoring all my contact attempts for a month, I was surprised to received my new citizenship certificate in the mail.