I've had the original iPad Pro with 64gb since it first released and have somehow never run out of storage. Maybe my problem is that I don't download games. I'd suggest using a USB drive for downloaded media though if you're planning to travel. All of the media apps I use (Netflix, YouTube, Crunchyroll, etc.) support them. That's worked well for me and is one reason I was comfortable buying the 64gb model.
Sorry, I thought I had done this with Netflix but I tried it just now and couldn't find the option. Then I googled it and it looks like it was never supported, I must've misremembered Netflix being an option.