Having been on the going to teh sun highway many times including when it is only partially open, I agree that it is worth seeing. Also, if you like to backpack, there are some great destinations in Glacier. I have packed as far as teh Canadian border.
If you enjoy the outdoors, you may also enjoy canoeing the wild and scenic of the Missouri River. It is worthwhile and I have even watched a cougar trying to kill a deer while on trips there.
I would especially suggest flying into where you can go watch the giant coastal browns catching and eating salmon at brooks falls. (Note: you can watch the brooks falls cams to get a general idea). On the way out to the falls viewing area, my wife walked extra fast and kept repeating, you are going to kill me yet, you are going to kill me yet. Then she suddenly exclaimed, “One of these days you are going to get me killed.” On the way back she was much calmer and considers that the highlight of our Alaska trip. But, on the way out she was terrified of encountering one of the bears.
I would also suggest the Glacier Bay cruise. The amount of wildlife seen on that cruise is well worth the trip.
Also, seeing Denali and especially doing a bus trip to the end of the road and a flight around the mountain area both worth it.
Also, speaking of Glacier park, during the salmon run, it is a good time to go to Apgar and view and photograph all the eagles that come in to eat the salmon.
In India, I would suggest Khajuraho to see those old “erotic temples” very unique.
Also, Darjeeling is worth visiting.
And, in early May, it is good to go into Sikkim and take a trip up to the end of the gravel road near the Chinese border at over 14,000 feet.
On the way at about 10,000 to 12,000 feet you go through the valley of flowers. The entire valley is filled with rhododendrum trees that are about 15 to 20 feet tall. The valley has red, white, yellow, orange, and purple iflowers n bloom on the trees that time of year.
Also, I would suggest several of the wildlife sanctuaries in. India such as Jim Corbett National Park for tigers and teh Sunderland for many types of wildlife. There are also several excellent wildlife sanctuaries in southern India.
I hope you get to do one or more of these suggestions.