Thanks for these. Unfortunatley only the first one works. The other two eventually time out...
I just retried the last two and both gave a 1.8MB/s download (though using a separate download manager rather than my browser). It might be worth retrying or using a different method (like a download plugin or another browser).
It could also be geographical with your nearest CDN node being oversubscribed as you suggest. In that case, my commiserations - and a note to Larian to consider a more reliable, distributed download system like BitTorrent (an option with HumbleStore/HumbleBundle downloads).