From England I would say your cheapest and best late December destination with warm weather and reasonable prices is going to be Phuket. There are some other Thai islands that might be a bit cheaper, but they would be more complicated to reach, and they’d have fewer activities for the boys. Here are some Phuket resorts good for families. You can see that the price range is wide from cheapest to most expensive. In late December it’s peak season so you’ll pay at or near the top of those ranges.
Australia’s capital has been voted the world’s most livable city—for the seven years in a row. If that isn’t reason enough to go, what is? Here's another: the artsy cosmopolitan city promises pleasant temperatures in the high 60s throughout November. Book a room at one of the area's buzziest spots, QT Melbourne, a design-centric boutique in the city’s fashion district.
Mexico’s spectacular Día de Muertos (Day of the Dead), bewitches Mexico City at the start of each November. Donning the skeleton face paint for the mass parades in the main Zócalo square is a must, but take time to step back from the party and seek out more intimate family celebrations where deceased loved ones are honoured with candles, sugar skulls and, of course, tequila. If you’d prefer to relax with a rum, then Barbados in November may be more to your tastes. The sugar-cane liquor is thought to have originated here in the 17th century and continues to be the local tipple of choice. Toasting the sunset from one of the island’s magnificent beaches is a quintessential experience.
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.