I have read many suggestions to take the train to Brooklyn and walk back on the bridge. We are going this weekend and was hoping to do this on Sunday and then go stand in the discount broadway ticket line in the Southport area. Is this walkable and is it too cold?

I meant South St Seaport. Also is it worth going there, vs Times Square, because of shorter lines and is it worth seeing?

Yes and no

South Street Seaport = no

Definitely walkable. Whether it's too cold or not will depend on the weather gods! We did it in January but lucked into 55 degree weather. You can also take a look at Wall Street, Trinity Church, and the WTC site while you're in the area.

You will definitely save time by going to the TKTS booth at South Street Seaport. Much shorter lines. The Seaport itself is not uninteresting, but is a bit too touristy for my tastes.

Thank you! We are going on Saturday so we will try it!

Unless things have changed, you can only get NEXT DAY tickets at the South St Seaport TKTS office.

Actually, Barry is wrong. You get next day MATINEE tix at the Seaport TKTS booth but same day for the evening EXCEPT right now, the Seaport booth is closed on Sundays.
http://www.tdf.org/TDF_ServicePage.aspx?id=56

Weather report is warm for the weekend.

Be forewarned that the TKTS booth at the South St Seaport is a little tricky to find. It's at the back of the building down what looks like a driveway as I recall.

If you are in the area, it's definitely better than going all the way to Times Square. and It should be a relatively short walk from the end of the bridge.

Thank you so much! It saves us from making many time consuming and exhausting mistakes, which we have often done!

You may want to bring an umbrella and some wet weather gear with you this Saturday - just something that I chanced upon with the local weather report.

Thank you!