WINNIPEG, Manitoba — There are many differences between the two Ghanaian refugees in Winnipeg, but the most significant comes down to a single thumb.

Razak Iyal and Seidu Mohammed became the public face of desperation among refugees in the United States after President Trump’s election. A trucker found them half-frozen north of the Canadian border on Christmas Eve. They had walked — sometimes waist deep in snow — across farm fields to avoid being deported from the United States. Their fingers were so severely frostbitten that all of them had to be amputated — with the exception of Mr. Iyal’s right thumb.

That single digit means he can fry up his own breakfast, pull on his clothes and pinch the knob of the washing machine to do his laundry. “That thumb I have left helps me a lot,” said Mr. Iyal, 35, a former appliance store owner from Accra, Ghana. “I thank God for it.”

Both men won permission to stay permanently in Canada. But while they are rebuilding their lives, their story has become a focus of sympathy and criticism among advocates in Canada, who say their fate shows that the United States is not fair or safe for refugees.