Quantum computers is definitely not a threat to Bitcoin. These computers cost millions of DOLLARS and undoubtedly be able to spread.
Well, but goverments, Google, Microsoft, all of them can use quantum computers.
You can choose to fight back with the little tools at our disposal. TAILS Linux operating system is an OS which has Electrum included and you can keep the seed in a safe place and restore it every time your run TAILS. This operating system doesn't leave any trace on your computer unless you want to, when it connects to the internet it only connects through TOR browser so government cannot do that much to stop anyone from using Bitcoin or be a threat to your Bitcoins.
Quantum computers are not build to be a threat to cryptocurrencies but to help aid NSA and other security agencies do their job better.