Usually if you log off before DC's , i believe you dont get rolled back.So let's say , you log on , do your TW bidding , log off 20-30 minutes. Log back on , if server DC i believe to be safe you will not get rolled back..My information might be wrong tho , it's only a guess ofc , maybe a GM can reply to it.
TW bids starts Wednesday 19:00 and lasts till Thursday 19:00 so you still will have a lot of time to bid, dont worry.