I struggled with 3G dongle and mifi for many years, then finally gave up and went for ADSL landline with a major uk provider. The improvement is phenomenal, really good bandwidth nearly all the time. I access the router from a tablet via wifi, so there is no umbilical and I can access from any room.
I can also use wifi in cafes, plus my provider has a router sharing arrangement, I log into anyone else's router hotspot.