Plans too ambitious?

Evening All!

I was just preparing to book my trains for my annual walkabout (usually in different countries) and, as a seasoned traveler, a little voice started chirping in my head that said 'too ambitious - too much travelling!'. So I thought I'd get some experts to take a look!

So the current plan (in December, all travel by train) is;

(Arrive on 15th)

16th-17th - Porto

18th - Travel to Lisbon

19th - 20th - Lisbon

21st - Travel to Seville

22nd - 23rd - Seville

24th - Travel to Madrid

25th-26th - Madrid

27th - Madrid to Barcelona

28th-31st - Barcelona

1st - Travel home.

The red flags jumped up when I realised I'm in Madrid Christmas day and boxing day - surely not the best time to see a city!?

I could move one of Barcelonas 3 days over to Madrid. My friends tell me they didnt have much to do in Barcelona and reading the winter guides, maybe they're right.

I'm expecting someone to advise knocking Seville on the head but that would give me like 4 days in Madrid and 4 days in Barcelona. I've been to enough cities to know thats a lot.

I'm interested in advice and thoughts though!

Thank you!