If you have booked a vacation in Australia, Mexico, Costa Rica, or any other tropical paradise spot where December and January is a peak summer time and beaches are bright sunny fun places, you would certainly look for a swimsuit before catching the flight. Buying a swimsuit in winter could be a problem and you may not find it easily at any local shop, so why not buy a suit online. Many want to try it on to see how it fits and flatters before wearing it in public, but where do you go shopping for a swimsuit in December?
Here is some suggestion for your beach textiles. Go to a sporting goods outlet, hey carry swimsuits all year long but it may not be the king you normally wear on beach but it would be more functional to serve your purpose. Try your luck and call big departmental stores, some of them have resort wear section where beach textiles are available year round, may be a bit expensive but at least you would have something in your suitcase sexy enough to wear on the beach.
One more option is available if you go online and search for virtual model swimwear try. You may find an online shop which has a virtual model feature on their website allowing you to type in your measurements and see what the suit would look like on you. This is the closest you can get to reality by sitting at home.