Better "Noise Cancelling" Headphones for Air Travel?


Full disclosure, I know next to nothing about headphones. I own a few pairs of ear buds and a pair of Bose noise-cancelling headphones for air travel and cutting the lawn. However, I have an upcoming international trip with my wife that seems a great excuse/opportunity to upgrade to a decent set of headphones. My wife won't care if she get the new set or the old, we can't both use the one pair, and it's a long flight.

For the trip, I'll be pairing my headphones with an iPhone/iPad & Dragonfly Red DAC that I already own. Budget is flexible but I'd don't want to go crazy...I'll probably spend <$500 but don't mind if people discuss other options within shouting distance of that amount to generate conversation.

My questions are:
1) How well do passive noise cancelling audiophile quality headphones cancel out the constant drone of a jet engine?..specific recommendations for those that would do it well, if any, appreciated

2) With that much background noise, are higher quality headphones even worth it or would I only notice the benefit in a quiet environment?..I'll probably stick to sharing my music with the family when in my own home so these aren't going to get tons of use outside of traveling.

3) Any recommendations for a pair of active noise cancelling headphones that sound better than Bose (QC35s) with the active noise-cancelling feature engaged?

Thanks in advance!
ethos123
I have not heard noise cancelling phones that deliver decent sound.  I would go the route Erik Squires recommended--good in-ear models.  They deliver great sound and do a terrific job of cancelling noise.  Some models can be a bit uncomfortable; if you are serious about in-ear models, you can get ones that offer custom-molded insert pieces that are made from an impression taken from the listeners ear by audiologist that fit hearing aids.  

The model of in-ear phones that I use comes from Etymotic.
I’ve been using active noise cancelling for a long time. Aside from the electronics, a major part of the noise reduction is the physical blocking of noise from covering the ears (and the padding around the ears). In-ear, regardless of quality, just don’t work as well in quieting down the ride...which is the primary objective. And remember that on long flights you’ll use them for sleeping, and over ear are much more comfortable. 
I have Bose QC 25's and they are excellent at eliminating ambient noise inside an airliner. My wife wears them without any sound input, personally I have to have music. I can't stand the noise on the plane, but with these it's 95 percent gone.
If anyone is interested here is the link with my selection of headphones for 2018 and a comparison of their characteristics https://www.bestadvisor.com/best-headphones
I hope someone will come in handy