Modern merino fabrics (and blends) are well worth considering for outdoor activities in my experience, however one needs to be smart and choose the right product type for the intended use. I have wool jumpers but I wouldn't go riding my bike in them but I do have new replacement Icebreaker tops which were purchased for riding and running and even day to day wear. I expect them to perform as well as my last pair of Icebreaker summer merino tops did when touring and running. I just hope the more the recent blends are more durable.

Anyway Ground Effect in New Zealand do winter cycling jerseys in merino which may be worth considering. They seem to have a good reputation as does most if not all Ground Effect gear.

Another option is something like the Terramar Thermawool Half-Zip which seems to be popular with the folks at Massdrop and is subject to a drop at the moment.

Personally I have a WoolPRO Scout or Agena Merino merino baselayer and I don't feel it rates against my Icebreaker so will be sticking to Icebreaker going forward (at a possible premium mind you) but the Terramar Thermawool Half-Zip may provide a relatively low cost way to get an idea of whether merino is for you.