How long should it take to close the gaps caused by a palate expander? (Photo)

I would like to get a palate expander, then Invisalign. After my palate expander treatment is complete, I’d like to have my two posted put in for my implants, then do the Invisalign treatment. The reason being is because I’m on the cobra plan due to my age. I was wondering how quickly can I get the palate expander out? Can it be held in place by the invisalign trays or do I actually still need the expander to hold them? And how long should my treatment in Invisalign take?