After living since forever in what they call an "outlaw state", I can assure you, Mr OP, that all of your concerns are extremely valid, and, indeed, you don't need an open war to start having REAL problems with your digital life.
Something as simple as a few bans or sanctions are more than enough to stop you, for example, from using your credit cards to pay for everything you take for granted, call it Netflix, iCloud or even a $0.99 app. And that's just the tip of the iceberg.
My advice on this? Be a pragmatic fuck. For example:
#1 Switch to open source or at least free alternatives for everything you can.
#2 If you see it coming, temporarily suspend your "good citizen" behaviour and pirate what can't be solved with #1. (assume the risks and learn to deal with them).
#3 Stay as local - your house local, not your country/union local - as possible, avoid "the cloud" if possible or create your own if it makes sense for you, a homelab or whatever.
#4 Stay as anonymous and low profile as you can; even if you support your government in a conflict situation, they can turn on you in a blink, for the right or wrong reasons.
#5 Familiarise yourself with things like Tor, VPNs and anything else that can help you bypass censorship and access blocked sites and services.
#6 Consider having additional ISPs as failover options, something as different as possible from your main ISP.
#7 Buy stuff to protect your electrical equipment: regulators, protectors, UPS and so on.
I'm not saying you have to do it all, take only what makes sense for you, but keep an open mind and consider that permanent peace and stability could be your lifelong situation if you are lucky, but maybe not. Says the guy who had it.
Trust me on this, I have become something of a cheap prepper, and not because of a war, it's far from that in here; just a few disagreements between governments, a few nationwide bans/prohibitions/sanctions, or a little bit of government incompetence/stupidity, are all you need to start having problems with international payments, problems accessing certain websites and services, problems with your Internet access, and even power outages, it doesn't take too much to start having a shitty digital life.