The headlamp isn't a sealed unit, so the condensation will probably clear
next the headlamps are switched on for a while,
but there is a potential problem as you have already seen ...
When you park the bike up, depending on how humid the air is,
if you then put a waterproof cover over the bike, any moisture in the air
underneath the cover, will condense as the temperature drops.
The condensation may form on the motorcycle, or the inside of the cover,
and these are not good conditions for long term storage,
which may lead to the onset or acceleration of corrosion !
Waterproof bike covers are designed to keep water from getting on to a bike,
but unless they have some good ventilation panels, they will also trap any exisiting moisture in.
Best solution - find a garage, preferably heated, and then cover with a soft breathable dust sheet.
If you have to leave the bike outside, and / or use a waterproof cover,
try and let the bike cool down completely before covering it up,
which can help to minimise the problem.
Cheers

