This is one of those dilemmas that only people on these forums would ever even think about...I used to have to travel for work, and was constantly trying to figure out what was safe / not safe, what's a reasonable risk and what's an unreasonable one.
I agree with above comments about "can you trust your in-laws" though. My XAW was staying with her parents after a bad relapse and I had a week trip I needed to take. The in-laws were the only option available, so it was either don't go or go while putting trust in the in-laws. I ended up going, and there ended up being an incident while I was gone, but the in-laws did the right thing.