Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Johannesburg to Vermont as you normally would.
Qatar Airways is one of the carriers that may have flexible change policies. You can use our site to filter for other airlines that may also have this kind of flexibility.
The Johannesburg to Vermont flight path was viewed by 38 users in the past month. Keep an eye out for changes in search interest prior to high and low season.