I would do what gave me peace in my heart. If going means you'd obsess and not enjoy yourself, then stay home.
If you think it's okay and your guilt about always having to be there is holding you back...then maybe go, because it would be great Codie therapy.
What's the worst you expect will happen if you send a friend and you're arriving a little later?
I agree with not telling him either way.
I felt I always had to be on call even just to reply to my son's texts and calls when with his dad--I remember my mom came to my house to watch my kids when I had a business meeting overnight three hours away. She was so safe for them (second to me), but he was stressed about an upcoming visit with his dad...I was so exhausted I plugged my phone in across the hotel room at midnight and slept so soundly for the first time in ages...awakening to a slew of 50 texts between midnight and 4am from DS saying he needed to talk to me, was scared, where was I, mom?, mom?, mom?...
Talk about horrible feeling the next day...we're past that point now. But for a while I avoided overnight meetings or took him with me. He needed that security. (Now he told me I could take a job three hours away if I wanted to and come home only on weekends lol)
If DD needs the security of you being close, that's different than YOU feeling like you need to be close. If she'll be okay (it does sound like she might be if you have friends nearby and could come home if need be)...maybe push yourself to go and not feel guilty. It's such a fine line between our kids REALLY needing us and us feeling that they do.
There's no wrong answer. Even if you go and she ends up needing you, that's fine.