Since the plant is so big, would it be better to cut it into sections before potting it up, so that each section can produce roots and get a better root/leaf ratio?
No! don't do that ..would dehydrate for sure .
Some people grow Vandas in pots in time the roots will crawl out , they hate to be repotted , I did grow mine in the house in wood slat baskets with large landscape bark (well soaked and rinsed ) in a south east window , watered till the roots were green , the cool mist ultra sonic humidifiers work well .Mokaras like a lot of light but beware of to much if short on roots and low humidity . Hope this helps a little . Gin