Verizon Unlimited Ultimate is the plan my wife and I are on. No need to worry about anything when travelling. Unlimited talk and text to home and within the country where you're travelling. Unlimited high speed data up to 15GB per month (while travelling), after that it's still unlimited, but you're not getting the highest speed anymore.
As DanS mentioned, if you are on Verizon, just upgrade to this plan for the month when you travel and you won't need to worry about a thing. I can't speak to other carriers.
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