Migrating large folder structure from PC to albums in icloud photos

I'm a long-time PC user planning to get an iMac. I am a hobby photographer and have a large collection (approx 0.5TB) of Jpegs and RAW files that I want to be able to access on my new iMac. They are stored on my PC in a folder structure that I need to preserve (or at least transfer to an equivalent album structure in Photos).

I am attempting to transfer these photos to iCloud Photos, so that I will be able to access them on my new iMac (when it arrives). I have downloaded and installed iCloud for Windows. I have run into a couple of problems:

I would love to be able to just copy my existing folder structure to the iCloud Photos folder on my PC and have it create folder and / or albums based on the existing folder structure, and tag the photos to those albums accordingly. This does not seem to be possible (if I create a folder within my iCloud Photos folder on the PC it seems to be ignored by iCloud).

I am happy (sort of!) to recreate the folder structure manually as albums but I can't find an efficient way to do this. Can I manage albums from within iCloud for Windows? Or even see existing albums and assign photos to them? Right now I can't figure out how to do that.

I can create new albums using iCloud in my browser, but unfortunately, the browser interface does not support uploading RAW files (only Jpeg) so I can't create an album then drag photos from my PC into that album.

If I uploaded all my photos in one go, it would be impossible to manually assign them to new albums. The only workaround I can come up with is to drag a single folder of my existing photos into the iCloud Photos folder on my PC, wait for it to sync with iCloud, then go into the browser interface, create an album, and assign those new photos to that album. This will take me days (and will still be messy as the newly synced photos don't necessarily appear in their own place in the browser interface).

Any help or workarounds greatly appreciated.