Hi,
Have you read this?, this has everything you need:
http://www.growsundews.com/
Drosera venusta don't go dormant, but you can still give them lower temps of about 50F or lower and they will come back from the roots, venusta will do fine in temps of 80F.
and yes, droseras are propagated faster in this way,(with pullings as well, if you want to have a lot, this will be the faster way, but if you want it to grow faster, then with pullings/cuttings), drosera seeds germinate fast, and they become weedy, your plant will self pollinate, then it might take about 1 month maybe 1month and half, unntil the flower is totally dark, and the flower stalk starts to darken as well, that's when you need to take the seeds, this can be done by carefully putting a piece of paper where the seeds in the flower cage(sorry i don't know the term(the bud) fall, and then take them inside immediatly, drosera seeds are really really really small, they are the size of a dust particle, even when breathing, they could fly away, so be very careful, if it has about 3-2 or more flower buds, then you will have somewhere about 300 seeds maybe.
Your plant is loosing the dew because the energy is going to the flower stalk, so don't worry, when its done producing the seeds it will have lots of dew again!
Can you post a pic as well!
Hope this anwer your question!
Good luck!