Not if he goes back to normal next year. If you don't think this year is a fluke, then I guess it can be compensated for, but there's no way this is going to continue and when he's playing like himself he's one of the best offensive defensemen in the entire league.
In his previous three years (his entire career, outside of this half season) he's 7th in defensemen P/GP for guys with over 200 games played... which includes the years that he had the same injury/surgery/recovery that Giroux had. Look at the only names above him...
Then for PP scoring... nobody compares... (notice games played)
So, not only do we have no defensemen who can step in and replace his scoring right now, but even if we assume Sanheim or Myers can get close, there's absolutely no reason we can't keep all three.
Keeping him is the only logical choice here. He's just too good and too valuable. No realistic trade that involves him leaving makes this team better.