I use Vodafone's 1GB mobile dongle with no problems. You can also buy 2GB and 3GB dongles and the good thing is that your credit does not expire after 30 days.
I would ditch 3 and go with Vodafone, which is the best mobile broadband provider.
Surface Pro (2017) vs Surface Pro 4
Where HTML5 is headed next
MacBook Pro v Surface Pro 5
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.