ILR for family member , not living in UK

[enm1sg]

I am working and living in UK on workpermit and my wife and son mostly living in their home country and vist me here in UK time to time .

I just want to confirm that if it will make any diffrence about gettting ILR / Naturalisation for my wife and son as my depandent when I apply ILR and naturalisation in due course of time .
Now the time limit for applying for ILR has been increased to 5 years . Can you please guide me how much time , I am allowed to be away from UK in this five year period before applying for ILR .