Yes you can but... it sux.
I upgraded from 8.1.2.0 to 8.5.1.0 and there are good and bad things.
Good:
- Caroussel is working again
- You may change icon grid to have more icons on the (home) screen
Bad:
- I lost TWRP and root
- Bootloader is now locked
- Power drain doubled (using Waze and...