Originally Posted by CaptainMiles

Guimarães is more historical than Braga. Braga's best sites are actually outside the city. How are you planning on getting to Guimarães or Braga? If you are relying on public transportation definitely do Guimarães, as the tourist site are concentrate downtown. If self-driven car, then it depends on your interests and the weather.

Why take the bus? I find the train more comfortable. Have you considered train? If you want to see the countryside, travel in the morning. If not, take the night. Keep in mind that at that time of year sunset will be about 18:00 and sunrise about 7:30.

That day trip is certainly interesting. Two things: 1. It's spelled Cabo da Roca. 2. Get some flexibility into your schedule and be flexible because of weather. Instead of being tied to Cabo da Roca and Sintra specifically on February 14, you may want to pick a nice sunny day for that and leave a rainy day for museums in Lisbon. You can do Sintra + Cabo da Roca + Cascais all in one day. Dinner in Cascais will be nice, but be mindful that on Valentine's Day the better restaurants may be fully booked.