Re-freezing top of cake

So, we had our cake after our anniversary, and it's still delicious. But I am feeling nostalgic and don't want to throw it away (there's no way we're going to be able to eat it all right now). What are your thoughts on re-freezing for the 2nd anniversary? It's already been re-frozen once - we had a slice at my parents' a few weeks before our anniversary, then stuck it back in the freezer and re-thawed after we returned from our anniversary trip.

Also, any tips on 'packaging' for refreezing? It's about half the size it was now, so I'd rather not keep it in the original box (which takes up a *ton* of space). Could I just put it in a tupperware and if so, should I cover that with saran wrap and tin foil like we did with the original cake box?

Help!