Centrally ducted heat pump quote and sizing question

Hello all!

I am a very beginner in HVAC questions, and am planning renovations in the appartment where me and my family are living.
This is located in an old plex, 2 stories, 3 appartments, built in 1944.

Our appartment has a ground floor and a basement, with about 1300 square feet per level, totalling 2600 square feet.

Aas part of the renovations, we will insulate, install a central heat pump with an air exchanger.

The quotes I have received so far are proposing a daikin fit model with the following AHRI reference number: 204875384

I live in Montreal, where it get really cold in the winter (regularly between -10 C to -20 C and less)

I am worried about the heating capacity on cold days given the 13700 BTU/h at -15 C (5 F) in the specs.

For some reason the HVAC contractors here do not count the basement, and tell me to add about 4kw of electric baseboards to heat the basement.

Is this really expected ?

I would have thought the benefit of a central system was that it could heat the whole house.

Do these quotes seem relevant in the context of the appartment I mentioned ?

I am happy to give more details if that helps.

Thanks for your help!

source https://hvac-talk.com/vbb/threads/2236260-Centrally-ducted-heat-pump-quote-and-sizing-question?goto=newpost