|You could switch BEFORE you start the download.|
I couldn't agree more.
Wireless is what it is....a convenience. Wireless presently cannot, and probably never will, be able to provide the same performance as a wired connection.
Since you've already figured out that big downloads go slowly over a wireless connection, the logical (and smart) thing to do would be to follow wanderer's advice and just do the big downloads on a wired connection. Problem solved.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.