update . . . I went for it . . . baked, torted, popped it in the freezer for a day, defrosted, filled, spackled, fridge for an hour, layer of buttercream, covered in fondant & tossed it in the fridge (in a cake box) for a couple of days. When I was ready to add the remaining decor, I took it out of the fridge & let it sit for about 2 hours to let it get back to room temp (I checked on it every so often and didn’t notice any sweating). The finished product was picked up this afternoon and eaten earlier this evening. Customer raved about flavor, moistness & freshness. No dryness . . . don’t know if that’s because I froze the bare cake first or not, but I was once told by another cake artist that freezing cakes tends to lead to a moister cake AND that fondant acts like tupperware.
In conclusion, I’m happy with the outcome & will continue to do this with future cakes.