What about the utilities, property taxes, maintenance and repairs, capex, etc. are any of those optional for you?

Seller financing, subject-to deals (taking over the seller’s mortgage), or lease options can create terms that work for both parties.

The other option I have not seen mentioned yet is finding a corespondent who can originate for you.

@Pat Aboukhaled I would ULS (unit lot segment) the primary house and include a clause in the call option that would prevent them acquiring the DADU.

I say that because every decent legit place I know of in market, yes offers the option of doing just tenant placement, for self-managing. 

However, I don’t yet have the funds for a down payment on another house, and I’m trying to figure out the best option for where to live while I rent the apartment.Do you have any recommendations for managing this transition or tips on finding a temporary place to stay?

I'd like to move forward with option "b".

Because I've been having the hardest time finding a new CPA, I wanted to open my options by considering virtual firms. 

I'm not sure if any also lend in Canada, but you might want to expand your search to include "non-recourse" just in case it leads to some more options for you.

The high return investment option in Oregon seems to be coastal short term rentals, and we haven't gone that route yet.