Yes!
Bought a Xeon 1265L for 65$ from Ebay. Unplug all, take out Mainboard, replace CPU, make sure to replug SAS cable and all others, reboot, done.
Oh yeah, and getting a 1220 v2 non L version you will definitly need an active CPU Cooler!
Switching from 35W G1610T to 45W 1265L increased temperature by a lot in my case.
Stock: G1610T (you can see the peak with Prime95 around 53°C lower is idle Temp.)
Xeon 1265L: (peaks around 80°C that's when the Case Fan kicked in from 18% to 45%, Idle Temperature is about the same)
I've compared Powerdrain by both systems.
Idle with 4x 6TB WD Red the G1610T uses 45W Idle and 55W Load.
The Xeon 1265L uses 45W Idle too, but goes up to 100W in Prime95 quite a bit more ^^
haldi's post in CPU Upgrade Gen8 was marked as the answer