You will have to do your own tests, but I develop Neopan 400 in D76 1+1, which is essentially the same as ID11 1+1. I have been using this combination for several years now, very good film.
I found with my total developing system that includes, camera exposure, developing and printing, Neopan 400 works best exposed at 320 ASA, developed in a Jobo rotary developing system at 21ºC for 12.5 minutes.
With this combination, I have virtually grain free negatives with beautiful shadow detail and marvellous highlights.
If I wish for a slightly faster film speed, then I up to 640 ASA and develop for 14 minutes at 21ºC as above.
800 ASA is quite doable, but I find Im starting to lose more than a bit of shadow detail; this is fine if the subject can tolerate shadow detail loss, but it can be problematic for portraiture. That said, today I shot a few rolls at my nephews wedding and exposed the film on one roll at 800, but I will be developing the film as though it was 1000 ASA.
With the roll exposed at 800 ASA, this was shot at the dinner and it is expected that there will be deep shadows with no detail.
What you are proposing, 1600 ASA exposure, will give you printable negatives, but you will certainly see loss of shadow detail. This isnt a bad thing, just a fact.
I would suggest that you do expose and develop your film as you have suggested, take notes. Maybe even push the film further and just see what happens, it is the best way to learn, plus its fun.
Every person develops and exposes film slightly differently, you should, in a reasonably short time, start to see what works for you. Once you find a roll of film that works well, figure out what you have done, then be consistent, roll after roll after roll.
Mick.