Best Way To Compress .tiff files from Scanned Photos

Hello!

I have been designated something of the family archivist, and have taken to scanning all the old famly pictures from the 1910s up through the early 00s. I'm keeping it all in Lightroom. When I started the project, I thought, "yeah, best scanner, best setting, why not?' -- And was doing everything as a .tif at 1200 DPI. Well, now it's taking up a tonne of space, and I was considering ways of reducing the size of each file. These are often black and white, or very vintage-y, not super sharp in detail, and I thnk don't warrand 175mb per 4x6 picture from 1985.

I've also noticed that the large files take a long time to register any changes in Lightroom. I feel like reducing the size will also improve performance.

But I also don't want to get to a place, years from now, when I try to make them into a photobook and re-edit a bit, and they're all pixelated and terrible. I want to be able to still edit the colours in lightroom and have enough of the data saved that I can still manipulate shadows and such when the time comes.

Any advice on the best setting to down-grade to so I'm not using terabytes and terabytes while still maintaining quality? 

Thanks in advance!