My father didn't wear long johns except in the bitterest winters, and DH never wore them at all. He wore M&S Y-fronts, from 1960 on (I have no idea what he wore before that. I do know that his mother bought them)
One grandfather, however, who was born in 1891 and who worked mostly outdoors all year, repainting the outside woodwork of council houses, in all weathers, and having to turn up onsite even if it was driving sleet or snow, DID wear long johns. (If the weather was too bad to paint, the men were paid half wages for that day, but only after they had reported for work, then stood around in the sleet for several hours before being dismissed. This was so that they would be too late to get casual work elsewhere and be paid again for the day. Couldn't have them getting more for a day of not being at their regular work! Needless to say, that and having been gassed in the trenches meant he had bronchitis every winter.)