I think you have your machine and basic equipment figured out.
For the fabric I tend to look through my patterns, Pinterest account, and anyplace else I store my creative thoughts! I pick a few likely projects and make sure I take the odd bits I have already with me....specialized rulers, hand quilting thread etc.. I decide how those patterns will be transported.....I like to leave a set at home just in case. Then I pick a couple that I definately want to complete and pull fabric. I don’t usually precut if the whole project will be done at the other location because extras can be a life saver. Make sure you take a pattern or two that could be easily sourced beyond what you are taking or out of extras. An EPP project that purchasing 4 or 5 fat quarters and would keep me occupied for ages is my emergency go to.