You don't quite know what you're talking about.
ICE doesn't control the border, CBP does. ICE comes in after you've crossed the border if you've overstayed or entered illegally.
CBP DOES have authority to take your phone without a warrant. We've seen this repeatedly over the last 10 years, even hitting the courts which have ruled in CBP favour.
CBP WILL use it to deny your entry if they find something they don't like. Just like anything else you have on you.
Same same Calgary loves America right now so if you're from Virginia you'll still be welcomed π