My wife and I are planning on doing a day trip (from Nafplio where we are staying 4 days) this September. One day we are planning on visiting Mycenae (get there in morning and finish by around 11), then quick visit to Nemea ruins, and from there hit some wineries in the area. The ones that as best I can tell don’t require any advance booking (and you can just show up) in the area appear to be Palivos Estate, Papaioannou, Domaine Bairaktaris (Ktima Bairaktaris),Lafazanis Winery, Domaine Repanis. Doubt we will get to all (and maybe there are others I should put on the list). Then back to Nafplio in evening. Any advice or recommendations from anyone that has done anything similar?
We did this and honestly it is a lot for one day. We had a group of 7 which only makes things more complicated but 1/2 of our group was not ready to leave Mycenae at 11. We did leave and go to Nemea which my young adult children liked better than Mycenae. There is a fabulous air conditioned museum (it was hot in June!) that we did not have time to see properly.
We then had lunch at a place recommended by some of the staff at Nemea.
We then went to a winery. I can’t remember which one at the moment but I will tell you we had a tour at 2 and that is as late as you could go. So I would guess your plan of multiple wineries will not work. I had made reservations the day before. I am not sure there is anywhere you can just show up.
The wine tour was interesting and different than in the US. We got much closer to the production that would ever be allowed.
Based on on the previous reply, you might try flipping the order--Nemea, then wineries and lunch, then Mycenae in early evening.
We visited Ancient Mycenae in the morning like you are planning, had a quick bite at a little taverna in Mycenae and made our way to Nemea for the wineries. I had a list of about 6 in the area that I was interested in, flagged them in off-line google maps and would use the previous winery's wi-fi to check where the next stop was and if it was open. The first winery also gave us some recommendations. I didn't make any reservations just hopped between a few - these I remember for sure - Ktima Palyvou, Karamitsos, Domaine Skouras. This would have been afternoon between 2-4pm (also in September) and we found most were open and very accommodating. We even got a short cellar tour at Domaine Skouras. With a big group, a reservation is probably preferred but as a couple, I wouldn't think you'd have any problem just walking in. If you are driving yourselves, maybe split tastings to avoid getting intoxicated. Its fun to buy bottles to take back to your hotel for the evenings.