I was going to take him, even though the family members who were 3 hours away waiting for us had said not too bring him due to everything that was going on, but like everyone else here has said, I need to support my husband and if that meant bringing our son, so be it.
I had our sons bag ready, some cold medicine as he wasn't too well, so that would have made the journey easier on him. Probably would have fussed for the first hour but it turns out I was going to get car sick during the journey. Sure the joys of having an IPAD these days would have kept him entertained anyway. But like I said, had everything ready for him to come with us, and at 1am I got an email from a friend who said she was coming on a bus in the morning and she'd stay with him the 3 days we were up. So thankful for everything she did, our son didn't even notice we were gone. Sure he would have gone home with her! 
The family members who backed out are regretting it, as I knew they would, very apologetic and upset with themselves. But obviously it just wasn't the right time for them, it happens, we all say something and then wish we hadn't. But maybe they'll think twice about offering help next time if they don't know they actually WANT or can do it.... 
Thank you all for your moral support and advice in my stressful time of need. It came at me all at once and being so tired and stressed I felt like I'd lost all confidence in my choices.