How long will cookies keep if I wrap them well to freeze?

Most of the recipes I use that can be frozen say they will stay good for up to 2-3 months in the freezer, so you might be okay with that window. I would wrap the cookies in Press 'N Seal (in layers), wrap the whole stack in foil and put that inside the Tupperware. The key is to keep as much of the air out so they don't take on any ambient flavors from the freezer or get freezer burned.

I would also check the recipes to see if you can freeze the unbaked dough and then bake them shortly before the event. I think with some varieties the texture of the finished cookies would be better going that route vs. freezing and thawing prepared cookies.

Yes, I think you could start now and they should be fine.

I do think it's overkill to do any wrapping over the Tupperware. That should be pretty airtight.  I'd worry more about the wrapping inside the Tupperware. A good amount of plastic wrap or Press n Seal or plastic storage bags would help make sure that any excess air inside the Tupperware stays away from the cookies.  

I prefer to freeze the dough and then bake over a few evenings for the best freshness

I usually make the dough, scoop balls, freeze the balls on a cookie sheet. Once frozen put them in a plastic bag. Then when I bake them I just have to arrange them on the cookie sheet and bake. Fresh cookies with a lot less work before baking.

I would think you could still make and freeze the dough well ahead of time (I do this all the time, make a huge batch of cookies, scoop into balls, freeze then bag to bake later as needed or wanted) and bake them 7-10 days out. As long as you have them stored in airtight containers they should still be fine even two weeks later at room temperature.

The baking part actually goes really fast once all the messy stuff and cleanup is done, especially if you don't have to change the oven temperature too much from batch to batch.