Looking for a good workflow to deal with large file sizes after Photoshop

I recently upgraded to a Nikon D850 which produces RAW files on the order of 37MB in size. I take these as DNG files into Lightroom. When I edit an image in Photoshop and then return to Lightroom with the image saved as either 16 bit lossless compressed TIFF or PSD (all layers flattened into a single layer), I wind up with a file size that exceeds 200MB. I do understand why this is happening, and if it is an image that is of really fine quality that I might want to someday print or do more with than post on the internet, then the file size is ok with me.

The problem is that I travel a lot to dance festivals and take lots and lots of social dance photos, perhaps 500 or more images in a weekend. And I will wind up retouching a lot of these images in Photoshop for one reason or another. In most cases the images are only posted as exported JPEG on the internet, e.g. on Facebook or Flickr, and so it seems to be a massive overkill to have the 200+ MB TIFF files lying around. On the other hand, I would like to retain all the retouching that I did in Photoshop, just in case I decide to do some more changes on the images later.

Can anyone who also has run into this same situation recommend a good workflow so that I can avoid spending my life savings on external memory storage? Is there an alternative file format after Photoshop that can be used? Should I save the Photoshop files as high quality JPEG instead? Or go down to 8 bit? Or does it make sense just to resize in Photoshop from the huge image sizes, say by 50% or 25%? What do people normally do in this situation?

Thanks for any good tips!