I''ll be travelling in Germany 3&4 Feb so quite interested to know if there's likely to be further strike action then.
Well, I think that mentioned here a couple of times already.
The dispute between GDL and Deutsche Bahn is going to escalate.
That means the strike period will become longer and longer (first 24 hours, then 2 days, then 5 days, then 7 days, then unlimited).
You might get lucky and avoid the strike. The current strike goes from Jan 24 to Jan 29.
Usually, there you will see at least one week of peace. So the next round is slated to start at around Feb 8 (my expectation).
Is there any requirement for a notice period ( like the 14 day rule in the UK )?
No !
Any period of notice (now its 2 days) is just a "service gesture" by the unions to avoid people getting stranded.