I need a free gallery plugin with a couple simple features

It’s been an interesting, but not very productive two weeks. I don’t need to blog or post or comment or whatever. I just need to display images.
Think event. If I do a dozen events a year, and at each one I do portraits of a dozen subjects, and I want to display 40-50 images of each of those subjects. Which means I’ve ALREADY got enough PITA work to do without having to waste massive amounts of time creating redundant stuff (galleries AND pages for EVERY subject of every event) in WordPress. I need a gallery plugin that will let me display sets of images (galleries? categories?) for an event on a page.
I don’t care if it’s categories, albums, or something else that lets me SIMPLY grab a bunch of images, dump them into a gallery, stick a
category on them, and display them on the page for that event…
AND, the gallery HAS TO PRESERVE THE ASPECT RATIO OF THE THUMBNAILS.

I can find a gallery tool that doesn’t butcher my thumbnails (Envira) but they want at least $100/yr to make albums.

I can find a gallery with categories that works adequately (Gallery) but it forces my thumbnails to be square – which NONE of them are.

And, unfortunately, it’s gotta be free or VERY inexpensive ’cause if it’s going to cost me $100, or worse $100/yr, I may as well stay with my current solution, which is $100/year.

So, reasonable or pipe dream? What are the aspiring but broke wedding photographers or school photographers doing?