I am in Ontario Canada, same climate as N.Y. for the most part.
I have a back split home with two cathedral roofs ( one at front of house one at back ) there are two skylights, there are 6 inch rafters on one side of roofs, 4 inch on the other side, soffit vents are located only on one part of the front roof  , these  are actually little screened areas at top of short side of interior wall that open up into the carport where the roof carries over the carport , and there are two small square vents at top of  each roof where there used to be very small ‘attic ‘ like space under the vents, these ‘attics’ have now been removed and we will have completely vaulted ceilings now , my research tells me that spray foam insulation is the only real option based on rafter depths and lack of soffit ventilation all around as well as skylights  , is that correct? Are there any other options I should be considering ? Is there anything to be concerned about with spray foam and creating a hot roof in my climate? My roof is fairly old but still in decent condition.. does age of the roof matter? should I be applying some kind of layer of anything under the inside of the roof in between the rafters before the spray foam? How best to block the vents also?
Should I be concerned about leaks not being noticed early due to spray foam?
I also have solar panels on one side of the roof that cannot be removed…
Is that a concern?

Thank you