I do what Sanderxpander suggested and use a USB wireless adapater - plug it in, turn it on, instant internet connection. When complete turn it off and disconnect - no more internet connection.
I understand the desire to remain offline, but it really is a convenient means to an end; more and more software is becoming tied to an internet connection so it's nice to have that ability if and when needed. FWIW, my DAW has only been online for a little over a year now because my studio is in a spare bedroom and nowhere near a physical connection.