Whilst overshoes and normal summer cycling shoes work OK for many people when road riding through the winter, this is a less suitable combination when it comes to off-road riding on a gravel bike in cold weather. The problem is that the worse the weather, the less rideable trails might be so there may well be sections of walking. Pushing your bike along a rough, muddy or snowy track is a surefire way to trash your overshoes.
All of which is a long-winded way of saying that winter boots are much better than overshoes on a gravel bike.
