[MichaelZuo]

I found it inordinately difficult to get humidity to a stable point in Canadian winters, because practically no homes are designed with relative humidity in mind.

[turtlebits]

Houses are designed to control/shed moisture, not control humidity.

It's fairly inexpensive get a standalone dehumidifier and just set a humidity target.

[MichaelZuo]

A house usually has several rooms. And in Canada humidification demands are much higher in wintertime then dehumidification in summertime.

So your looking at literally dozens of humidifiers and dehumidifiers to maintain the optimal 40% to 60% range at all times in the average sized house.