The couple escaped without injury and are staying with a relative nearby.
RCMP say one volunteer firefighter received a minor injury when a medical oxygen tank exploded.
Speaking from Nova Scotia, Dan Bedell, a Canadian Red Cross spokesperson, said a donor has come forward with a replacement for a motorized wheelchair that was damaged in the fire.
"They did lose everything in the fire, including a number of medical devices, for example the man had a motorized wheelchair that was lost in the fire," he said.
"But since it's been mentioned in the media, we've already had an offer of a replacement that was called in to our contact centre in Saint John."
The cause of the fire is not yet known.