With FireCapture or SharpCap you can acquire a dark frame to be automatically subtracted by software during acquisition. Thus the frames remain clean, even if they last 15 seconds, and Deep Sky Stacker will perform alignment relative to real stars, not hot pixels ! Simple and very efficient.
You only have to the survey how the sensor temperature drifts during the night. If the temperature noticeably changes, then stop the acquisition, take a new dark frame then start acquisition again.
Once you have the series of frames, remove the bad ones (with star trails, clouds...) then stack them.
