Yes, whenever car or tire manufacturers are specifying tire pressure, it is a "cold" pressure.
The maximum tire pressure specified on the tire is exactly that, a maximum. It is not a "recommended" tire pressure, unless conditions that the tire is experiencing calls for the maximum.
If you were an anal retentive person, you would be adjusting your tire pressures upward or downward depending on whether you were traveling with a full load of passengers, lots of luggage or other load, etc. In the real world, What I do is see what the auto manufacturer recommends, see what the maximum is on the tire, and then split the difference. On the cars I drive, I typically run about 35 psi.
And tire pressures do drop on their own in winter due to the fact that gas (air) contracts when chilled. So, if you last checked tires in warmer weather, check again when it gets cold. And then check again when it warms up again. (Of course, if you are the aforementioned anal retentive, you would be checking every two weeks in any event.)
Years ago, I got tired of going to the service station for air, and I purchased a home compressor and good tire gauge. As a result I really can check tires totally "cold". One of my better decisions.