Yup, rehab was my "Plan B" that I promised myself if I was still drinking after 90 meetings in 90 days. Never needed Plan B, because I never picked up another drink using Plan A.
This is actually perfect timing, too, while he is away at rehab. You can focus completely on yourself and your own recovery without the distraction of living with someone else who is drinking or newly sober. You can actually create your own "rehab" by working diligently on your own recovery.