The facts about the law are quite clear. The penalties and the how they are implemented less so.
Clearly there is a risk involved. Probability of having a problem is low, but Consequences potentially severe.
That said, risk can be managed. If you chose to do so, the main risk mitigations in my mind would be to pay attention to the good advice copied below:
The biggest concern I have would be presenting in immigration as a family...
go through immigration separately, and the child travel with only one parent.
as long as he and his partner don't show PDA.