This cold snap is not caused by anything to do with the sun that is a complete misunderstanding of what a solar minimum is. This cold snap is caused by unseasonably warm air in the arctic (+20 degrees C). No one (especially you) knows when there might be another grand solar minimum as these things are not predictable. It is expected we might get one this century. I suspect you are misquoting a bunch of people; e.g. since the IPCC target is 2 deg C by the end of the century why would anyone mention 2020. I suspect "polar ice cap meltING rather than melted. I note that the arctic ice has been melting and that the northwest passage is basically open (not recommended!) on a regular basis since about 2013.UK's only hope is that this "snap", which is just the start of this solar cycle minimum, with the worst still years ahead, around 2021-23, and then a grand solar minimum on top, a Dalton or possibly a Maunder, breaks in the next 2 days, as if this continues past the weekend, we are looking at food shortages, mass deaths from hypothermia, not just in the elderly, and quite possibly civil breakdown, as food supplies become affected, with the notorious supermarket just-in-time supply chains from field to shelf.
We've only ourselves to blame, as we are an infantilised society, distracted by bread and circuses - football, Z-listers, crappy royal weddings etc - and the under 30s believe smartphones are the be all and end all of everything.
British people believe AGW more than most other peoples, lacking the gumption to question the 30 years long propaganda. You reap what you sow, and the whirlwind literally is here, with -25 deg C windchill, when we were told just a deacde ago by charlatans like Gore, Blair, Stein, Viner... that 'snow would be a thing of the past', 'the world would have warmed by 2 deg C by 2020', and the 'polar cap melted', and 'the north west passage opened up'.