Wendy -

They make small sized cardboard box cranberry juice. One box makes 8 cosmos. I have a flask that I bring Cointreau in. Limes seem to usually be the problem. I've had a hard time getting them on some itineraries. But I learned a new martini called the South Beach that you make with Cranberry and Orange Juice. No lime needed.

1/2 oz Cranberry Juice
1/2 oz OJ
1 oz Cointreau
1 1/2 Oz Grey Goose L'orange (regular will do)
splash of grenadine
Shake with ice and garnish with Marchino Cherry and Slice of Orange.

Editing to add that we can have Martini Night in our room. Oh and they've given me Cranapple once time and it was not so good. I will bring some Cranberry. And Frank wonders why my carry on luggage is so heavy.