Maybe look at getting a 4G hub (5G maybe next year)? I'm pretty sure Vodafone are selling such a device.
Problem is trying to get a decent bandwidth package at a semi reasonable price if you actually do anything other than light usage. Generally web-page loading times and latency in general isn't as good as a fixed line but generally fine for stuff that buffers like video but then you run into the download limits quickly :s
And that is assuming you get good reception - I'm kind of in this boat at the moment though not as bad - moving from where I have multiple 80/20 lines to somewhere that fortunately looks like having FTTC but speeds more like 20Mbit than 80. Looking to supplement with a 4G connection but unfortunately it looks like a dead spot for Three but other providers like Vodafone seem to cover it well but most of their packages are 50GB or less.