Hi,
Without meaning to state the obvious, your problem is due to a difference in temperature between the inside of the car and the outside. That's why the A/C solves this problem by reducing the temp of the inside so it matches the outside.
One way to eliminate this is to warm your windsreen before starting your journey. Put warm windscreen blower on for a few minutes so that the glass warms up. By doing this you warm up the glass right the way through and condensation/mist should be eleviated.
Good Luck
Gill
October 2012