I think this may be related to the latest update, but downloads have become incredibly slow on Origin.
They are seemingly maxing out at 40KB/s on my system when I can normally get 512KB/s-1.5MB/s on steam downloads depending on time of day. I suspect it is an issue with the (imperfect) http stack or the (missing) internet connection detection routines in Wine.
I will look into the issue. In the meantime, according to a similar bug at the wine project you can extract your download URL from the +winhttp debug log.