No reservation allowed at St. Mark's Basilica

The Basilica opens for visitors at 09:45. If you get ther around 10:00 you should have no problems with the line . Actually November should not be that big of a deal. Take the time to go to the musuem upstairs. It is the stairway to the right as you enter. Costs around 5 euro and gives you access to the balcony insode and out to see the original horses inside and the copies out on the loggia. Good views over the Piazza. Also you get a lot closer to the mosaics.

If you check a bag at the official bagcheck nearby, they hand you a ticket that allows you to go to the front of the line. It's an old RS tip that comes in very handy if there's a line. Happy travels.

Thank you for your responses. Very helpful.

Yes, the bag trick is awesome! It allowed my wife and I to skip the line and walk right in!! And the upstairs museum is worth the 5 euros in my opinion...bring your camera...just don't use it in the church! But it is nice to have once on the balcony upstairs looking down on St. Marks square. Lines are also better early and late, and in November probably much much better.

We are in Venice right now and we went into St. Mark's around noon today...we waited in line about 5 minutes at the most. I think you should be fine. It doesn't seem terribly busy.

Even during the busiest times of year, it is often possible to walk right into San Marco near closing time. The biggest crowds (from tour ships) hit Piazza San Marco around 10am and leave by late afternoon. Then the city is yours.