My first thought was Goa, which you say you’ve been to before, but maybe you don’t realize that there are about 20 different beach areas that are different from one another in terms of vibe and types of visitors? Personally, I found that Anjuna and Vagator were both kind of mellow but also busy enough and easy to meet other people. But if you don’t like those, there are many different beaches in the south, which I’ve heard are also great and draw different groups. It’s something to think about because it doesn’t get much cheaper than Goa for beaches anywhere in the world. -Roger
This is a difficult question to answer without quite a bit more information. First off, it’s obviously going to be pretty cold in most of Europe that time of year, although most of the major cities aren’t known for accumulations of snow. As long as you are okay with cold weather then it’s mostly down to budget and your main interests. I’m guessing that you haven’t been to Europe yet since you didn’t mention any places that you’d prefer to skip this time.
If you are interested in a place that isn’t focused on beaches in that area then I’ll point you to some recent answers just above where I mention the charms of Chiang Mai in northern Thailand, or Luang Prabang in Laos, and/or Siem Reap in Cambodia. All of those are wonderful places with temples and other sights, and they are quite affordable once you are there as well.
If you're determined to travel during the holiday periods, though, book your vacation flights, hotels, and cruise far in advance. If it works with your schedule, fly on Thanksgiving Day or Christmas day; those are the least crowded days of the holiday season. And if at all possible, avoid traveling during weekends, on the days right before or after the holiday, and late in the day. It's not only crowded at airports but also northern storms can wreak havoc and create weather delays that cascade across the system.
Few people travel between Thanksgiving and Christmas—specifically, from the Tuesday after Thanksgiving to the Thursday or Friday before the peak Christmas rush—so you can enjoy substantial savings off peak-season rates (four nights for the price of three, seven nights for the price of five) and your chances of an upgrade are good—if you book through a Caribbean specialist with clout.
Trekking in Nepal during peak season might not sound like the most sensible choice for penny-pinching backpackers. But you can still enjoy the ideal weather without spending a fortune on in-demand hotels and expensive permits if you're happy to swap big-name trails, like Everest Base Camp and the Annapurna Circuit, for quieter treks to Kanchenjunga Base Camp and around the Langtang Valley. Idyllic conditions (dry but not witheringly hot) are also on offer in Rajasthan, one of India’s most vibrant and varied states. Chug between notable, attraction-rich cities like Jaipur, Jodhpur and Udaipur on an atmospheric and wallet-friendly Indian train, snacking on spicy pakoras and sipping sugary chai en route.