With a raspberry pi you can use a picam (dedicated camera board). I've used one for a timelapse over several days, and in my reading for that found people who are doing much longer timelapses. The picam quite a decent fixed/manual focus cane and you can fix the exposure, use auto exposure, or take one photo with each mode, storing in separate folders. The pi will run indefinitely for such a simple task. You could use a USB webcam instead but may not have so much control (you could even use both). In my case I also used the pi to trigger an old dSLR.

It will of course crash if you fill the (boot) SD card with photos. So you should reckon on using the main storage as a buffer unless you know the whole series will fit with some headroom. But as it runs Linux you can make use of even a patchy WiFi connection to shift photos onto networked storage (rsync perhaps) which would be good for a progress website. Syncing onto a USB stick and periodically swapping out the stick is another possibility but you'd have to check how well it remounts.