I'm afraid Daisy may well be right but trying to be optimistic, if it was near the house and sheltered, for example, it might not quite have experienced -5C. According to this Florida production guide for Norfolk Island Pine:
"Norfolk Island Pine will tolerate a wide temperature range. High temperatures (95° to 105°F) have been observed to cause noticeable tip damage if accompanied by dry winds and clear skies, whereas low temperatures (30° to 32°F) can cause growing point abortion. Temperatures below 25°F can cause severe freeze damage, especially if accompanied by wind. Suggested production temperatures are 60° to 90°F for seedlings and liners and 45° to 90°F for potted trees."