We went to Spain in November. We loved it! We did Sevilla, pueblos blancos, Granada, Cordoba, Toledo, Segovia and a bit of Madrid. Maybe a bit chilly at night, but we'd wear a sweater. I think you also could do Barcelona/Catalunya in Novermber. I was there in January and enjoyed it.
We went to Italy mid October-1st week of November. We decided we wouldn't do Italy that late in the fall again. Very wet. When it wasn't raining the air temp was very comfortable. Florence was 70 degrees or so. We did have fabulous weather in Rome. 70s every day, no rain. We also went to Amalfi and had one rainy day/one beautiful day. Our day in Pompeii was 70 degrees and sunny. We went to Lake Como where we made do with mostly rainy weather. CT weather was nice, but it was forecast to not be, so they closed all the trails. We might consider Sicily that time of year, but I don't think we'd do the rest of Italy.
When you get to late fall/winter weather, I think the trick is to go where you know it will be warm enough with limited precip, or a place with bigger cities with both indoor and outdoor activities.
I've not been there, but I would guess mid and southern Portugal would be nice.