Couple of things to try,
First clean the inside of the screen really well with proper car glass cleaner.
Remove any fluffy rugs, toys etc that can hold moisture in the car.
When you drive up to park, for the last mile or two make sure the AC is turned off and the heater is on. You want the ventialtion ducting nice and dry. The AC matrix constantly generates condensation which sits there waiting for the engine to start again. If the AC is off for a while before shutting down, the vents will be dry.
If you have the time, throw a bucket of hot water over the windscreen before you get in. Heats up the screen and demists the windows. Ive done this on all the cars I've owned when they have been frosted, or really badly misted up. I keep a 2 litre plastic jug in the kitchen, fill it with hot tap water and throw it on the screen as I leave in the morning, The warmth demists the screen and it stays demisted long enough to get engine heat up on the screen. Never had a crack or damge in 15 years.
Buy a dehumidifier cartridge for caravans and leave it on the dash when you leave the car. They are electric rechargeable things that hold off condensation in caravans. When they are saturated, you plug them in. They dry out and are ready to use again.
Next to last option, Go out, turn on the car, leave the fans on high and temp on hot, use key two to lock car, go back inside and have a cup of tea while it demists itself. This depends on neighbourhood.
Final option, buy or install a remote strat alarm system, same as last suggestion but more secure!
2005 Focus C-Max 1.8 Petrol Ghia + Sony 6 disc, 2007 tail lights, Led bulbs all over and HID front fogs.