Possession/primary dwelling mortgage requirement question

[Daniel Pearson]

How much time do you have to live in a property to fulfill the requirement to live there for a mortgage? We have a house we're considering buying. It would be our primary residence. But we also have a camping/RV trailer and would like to airbnb the house. At what point are we considered not to be living there if we spend a large portion of time in the trailer instead of the house?