Leaving them on the cement is usually fine. Since eventually most roses go in fairly large pots, lifting them has its own issues.

They should stay out long enough that they get the idea winter is here. Usually, I end up hauling them in and out at least once since we often get a cold snap around the middle to end of October. There are a couple of nights below freezing, then things warm up again. I pay a lot more attention to when they come out in the spring, but I think the fall routine is something like they go in the garage for temperatures below around 30 (freezing is not the trigger point at all) They go in for good if temperatures are going to be in the low 20 for at least a week.

I have mine on wheeled pot trolleys to make them easier to move around and I just leave them on those to winterize them. I don't like putting mine on the cement because in my opinion the cement pulls moisture from the pots and dries them out too much. They need to have moisture all winter even though they are dormant.

In the past I used to start winterizing around Halloween. Lately, however, it's been warm way past that time and I've had blooms as late as Thanksgiving. For a few years we winterized on Thanksgiving weekend but last year we didn't until the second week of December. Not sure is it's climate change but it has been getting later before they go dormant.

I really can't give you an estimate of when it would be right for your area. You have to play it by ear and watch the weather. You'll be able to tell when they've stopped all signs of growth. Usually that takes at least a couple of hard freezes with temps dipping into the mid 20s. The leaves will start to look dried up and shriveled and if you have any tender new growth it will look frost bitten and wilted.