I live in a bungalow that was built in 1994. It has timber, double-glazed windows, all with trickle vents fitted. The house is aligned east to west. We have always had condensation on the windows in the front (main) bedroom, which faces north and is at the east end of the house. Opening or closing the vents has no effect on the condensation. Sometimes, if the outside temperature is particularly low, we get condensation also on the window in the back bedroom, which is unoccupied and which is also at the east end of the house. Fitting trickle vents would not solve your problem, in my opinion. The only way to prevent condensation on windows is probably to leave them open all night, which would not be a good idea.