but with modern knowledge and technology, you'll be able to get out of the way.

Out of the the way of what? If it is anything like Krakatoa it will cause a mini ice age. More likely it would spew for years pumping particles into the upper atmosphere reducing the power of the sun. And the ice age would be more like the middle ages. The years of no summer. Frost Fairs on the River Thames.

Renewable energy from PV? Climate change skeptics? And maybe a whole raft of satellite comms, including TV, would be curtailed. It rather depends how much carbon gets thrown up.

And don't rely on GPS too much, it might surprise you. FWIW the Russians have form on scrambling that on their borders and around grabbed territories like Crimea.