I don't know the exact TLS shut down dates, but it's usually two weeks in the August 1 to August 20 bracket, plus from 24th to 31st of December. Some workers however remain active on the site when the factory is closed.
I am not aware of XFW shutting down in the summer. Maybe in December ?
Does anyone have an overview of the TLS site? Some kind of map? Unfortunately I do not really know what is located where whenever I switch on flightradar. Ok, the Delivery Center is obvious ... but the rest?