Tier 2 General extension or ILR

[asdcjb]

Hello Forum members

I have a query related to my unique position. I have tried to find if anyone has a similar situation on this forum but have not found anything so I am posting it separately.

I was first issued my Tier 2 General visa on 1 Sep 2014 till 30 Dec 2015.
I got an extension on 1 Dec 2015 till 14 Aug 2019.
My office is extending my contract till 31 Dec 2019 and might extend further till 30 Jun 2020 which I will learn closer to Dec.
I would like to take advice on whether I should apply now under Tier 2 General to extend to 31 Dec 2019 or apply in Aug 2019 for ILR straightaway. I feel the latter is risky as it is too close to visa expiration. Also what are the rules on staying while ILR has been applied after visa has expired.
Fyi, my husband and daughter have been on my visa as dependents from the beginning.

[CR001]

You can apply within 28 days before 1st September 2019.

If you apply for ILR before your visa expires, your existing visa condition continue and you have section 3C protection until HO makes a decision if you apply by post or you can apply in person for a same day decision.