Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Winston has stayed fairly steady in American naming for generations. All-time it's been given to 32,956 U.S. babies, the 796th most common name by sound today, peaking at 866 in 2019, with 830 in 2025.
Winston has no common alternate spellings by sound.