Cell phone plan advice

I currently have a home landline and a cell phone plan with koodo. I would like to port the home landline number to koodo but I also don't want to loose the current koodo number. I was going to port the home phone to a second line on koodo which would be be $25/month for the cheapest plan with unlimited minutes.

If I don't use data on that line but have it as a second esim line(primary being physical sim) on my iPhone XR can I still use wifi calling since the reception is not great indoors or they will charge me pay per use data if I use wifi calling?

Also, I intend to use the home phone number as my primary cell number so I was going to port my current koodo number to voip.ms but I have a grand fathered koodo plan, is there a way to transfer this plan to the second line before the number gets ported(like do a plan swap between both lines)? Or I can only use whatever plans are on the market at that time?

I considered using another carrier to have a cheaper plan or go prepaid but I can't do prepaid since I need WIFI calling and I am in Quebec and Freedom mobile is not available here and I Fizz mobile(freedom equivalent in Quebec) says is not available at my address probably because its in the country side and not in a city.

Anything else I should consider to be able to keep both phone numbers while being as cheap as possible with WIFI calling? Thanks!