Thank you for your replies.
As always, nothing is simple. I thought that once I have guiding all my problems will be solved and that I can do 10+ minute exposures. Last night I realised that, while the mount can do it, the light pollution severely limits the imaging time. And now I know how bad the noise is as well.
This is funny, last night I took darks for 5min@ISO1600 and when I looked at them today I initially thought I forgot to put the cover on the scope. It took me a while to realise it was noise as the stars "did not look right"
