205kts in my 172 a few weeks ago coming back from Guernsey and 280kts a couple of years ago in the baron. Slowest was the same Cessna flight out to Guernsey when I had a 46kt ground speed at one point!
A C172 has a cruise speed of say 100kts. If you were flying into headwind then that suggests a wind speed of 54kts ?!?!? What on earth where you doing in that wind ? Surely the C172 would break apart easily ?