Foggy windows is a sealant failure in the thermopane unit. A thermopane unit is 2 pieces of glass, sealed together for insulation value. Once this seal is deteriorated, the insulation ability is reduced and condensation forms in between the unit forming a cloud inside the glass. 

A specialized manufacturer is required to order the new unit, which does take a couple of weeks, but saves you money. 
The only solution is to replace the thermopane unit.