Rabbits normally do very well in cold weather (much better than heat, actually), but this does hinge on their ability to grow the appropriate coat. When weather is extreme (either heat or cold), it can be dangerous to put an indoor rabbit outside or bring an outdoor rabbit in. Make sure there's not too big a temperature difference when you're moving her.
That said, I don't see how temperature changes would cause poop issues like you describe. As Blue eyes and JBun have said, as long as your rabbit is eating and pooping, it's not a medical emergency... however, you're right to be concerned about smaller poops. Typically, smaller poops result when a rabbit isn't getting enough indigestible fiber in their diet. Cutting back on pellets, removing treats and encouraging more hay eating is key to getting her poops back to normal (replacing her hay once or twice a day even if it hasn't been eaten can help... never mind that the stuff you pull off the bale is the same as what's in the manger, for some reason they're still more likely to eat what you've just added).
As Sharda Hartley said, some rabbits ARE a lot pickier... I have to mail order hay because mine utterly refuse to eat the Coastal hay from local feed stores. Also, rabbits DO drink more from bowls than from water bottles and hydration is also vital to a healthy GI system.
