By the Grace of Allah, I have so far memorized 20 juz. The hardest part for me is being able to keep up with my reviews while I am memorizing new surahs at the same time.

Question
Assalamu Aleikum
Jazakumu Lahi khairan for all your efforts and advice to the muslim community around the world. By the Grace of Allah, I have so far memorized 20 juz. The hardest part for me is being able to keep up with my reviews while I am memorizing new surahs at the same time. Thus I come to you as a student needing advice on improving his review schedule. My questions are the following:

1) How many juz should I review daily?
2) Whithin how many days should I, at least, be able to complete my daily reviews of 20 juz?
3) Can I also review by listening to a reciter such as Mohammed Ayyoub or Minshawi?

May Allah help you and grant you the highest place in Jannah for your effort, Amiin

Wa salamu Aleikum

Answer
Wa alaikum assalaam wa rahmatullahi wa barakatuh,
Masha' Allah tabaarak Allah!  Your news has indeed pleased us a great deal and we ask Allah to make easy for you the remaining 10 ajzaa' and that you work will be accepted by Allah. 

It is always difficult to memorize new parts while keeping up the old parts, but a rigid schedule should make that less stressful. 
The minimum amount of review should be 1 juz' per day, but it is much better if you can do more.  If you could complete your review in one week to ten days, it will strengthen your review and make it easy for you to firm up all your memorization once you have finished, insha' Allah, so you can be tested in the whole Qur'an.
Reviewing by listening alone is not enough.  If you you recite in your review and later or earlier listen to the recitation, that will help you, but only listening without you yourself reading and being checked or checking yourself will not give the desired results.

May Allah reward you greatly for giving us your good news and for your kind dua'.  We remember you from years ago as you had less memorized and were starting on your wonderful journey.  May Allah grant that you receive an ijaazah with a high sanad in your recitation and make you of the best of the Muslims, those who learn and teach the Qur'an.  Ameen.
Wa assalaam alaikum wa rahmatullahi wa barakatuh.