My thoughts....

Mavic mini is OK. But it's slower & probably not for high winds, which is what I'd call 10 mph +. It really needs to land on a hard surface due to the short landing gear. Not easy to grab from a hover either like Phantoms

Not sure how many hrs you can get on a 64 gb card, but why are you asking 4 hrs? You will get comfortably 20-25 minutes per fresh drone battery. So you'd need 10-12 batteries to fly 4 hours.

Cards are relatively cheap, so I'd change them out every 2 flights.