Hello Alenka, Good job on the dormancy. It sounds like everything is as it should be. I would wait until winter is almost over so that the plants will come out of dormancy just after you repot them. That should be sometime in February to March. If the old moss still looks and smells normal (for moss anyways), you can leave it and just repot the whole clump together in a 5-6 inch pot. Venus Flytraps clump in the wild so no worries there. You can let them grow like that for a couple of years and then try to seperate the rhizomes of the largest plants for repotting in different pots. Don't worry about that for now as seperating Venus Flytraps should not be done too often. Make sure to get only unfertilized moss and perlite for potting mix.

Probably any root pruning should be done just before they begin their growth .. so that would be around April. If you're just potting up to the next size, and the plant is rootbound, I do not think it hurts to repot in the early summer. I do all my repotting outside, usually in June. I just don't have the room to do it indoors when the weather is cold (and I'm too much of a wimp to do it outside when it's cold!). By June the plants are really getting going and are putting out a lot of new roots. As long as I don't damage the root system too much, they don't skip a beat.

Do the sarracenia in late winter early spring, although they can probably stay in those pots another year or 2 it looks like. If the Sundew is tropical any time.

What size is that pot? I like it. The smallest I have found around here is 4-inch. Of course, my choices for shopping are Home Depot, Lowes and Walmart. I don't think it is really necessary to repot at a certain time. It depends on what you like - and if the plant keeps tipping over the small pot. I prefer a pot shaped like an azalea pot or an orchid pot for better stability. My plants stay outside and it can be windy. I have pruned lower branches on this plant and it is still in a 4-inch pot after 2-3 years. It needs a repot for fresh potting mix, but otherwise is fine in this pot. This is also a 4-inch pot. If you use a very well draining mix, a slightly too large pot won't matter as much. But with a water retaining mix, larger pot means more soil and longer to dry.