Can spanikopita (or other phyllo foods) be prepped in advance? I offered to cook for an event for a friend. Later, the request came that the food should be "finger food". Grumbling aside (I hate tedium), most the finger food recipes I know have substantial prep and I don't have a lot of time beforehand to cook. I'd like to have as much "oven ready" things made the night before. One recipe I have and like is for spanakopita. In this one, the filling is wrapped in little parcels of phyllo and can be baked. Is there a risk in chilling the filling, doing the wraps, and putting them in the fridge? If not, how should they be stored and how far in advance can this be done?
Yes you can.

Anecdotal, Mom makes batches of small spanakopita in advance and freeze them up for later use. 

The filling should be cold when you are assembling the spanakopita.

(edit)You need to bake them before freezing them.

I would store them in the fridge in a plastic container in a single layer.
If freezing, put them on a baking sheet and freeze them in single portions, put them in a freezer bag.