As for Indonesia vs. Philippines, I’ve been to Bali quite a few times but I haven’t been to Bandung. And for the Philippines I’ve spent time in Manila and in Tagaytay just to its south, and I don’t think I’d recommend those for a longer trip. And I also spent two weeks on Boracay Island, which is quite nice, but it’s small and also a place I wouldn’t recommend for a longer trip like yours. For information on Indonesia you might go to my friend’s site – travelfish.org – which is an excellent resource. Unfortunately, they don’t cover the Philippines yet. Best of luck with what you end up doing. -Roger
Say Hydrated – This is a no-brainer and one of the most significant challenges for me. I never drink enough water, but it was hot this week in Florida when we were at Disney, and I could tell such a difference in how I felt when I was hydrated. I felt like it made it easier to stay strong and stick to eating low carb/keto as it helps to quench false hunger.
Sri Lanka doesn’t really have a good infrastructure for budget travelers at this point. There are loads of nice hotels if you are willing to pay US$40 or more per night, but almost nothing below that except for a few hostels. I haven’t been to Palawan but I have been to Boracay and Palawan can’t be too much cheaper. Boracay doesn’t have many budget options either, so my guess is that Thailand or Cambodia is your best bet.
Uruguay is an interesting place. It seems to be a less modern and less developed version of next-door Argentina. Buenos Aires is a larger and more interesting city than Montevideo. There is a town there called Colonia, which is worth a couple days if you like old and charming cities. But most people who go to Uruguay either go to one of the posh beach resort towns (mainly Punta del Este), or they go to the tourist cattle ranches, which are surprisingly popular. If you haven’t been to Argentina yet you might find that it has more and different options, such as the Mendoza wine region and the mountain resort town of Bariloche.
Another destination that might not exactly have “great” weather in December, yet deserves to be on the list, Sharm el-Sheikh is famously Egypt's most popular Red Sea beach resort. Those following the news might still hesitate to book a trip here, whether that is a rational decision or not. But at the very least this is one to consider in the future, as it's an amazing bargain once you get here.
Otherwise the big draws are the Great Barrier Reef, which is obviously focused on diving, snorkeling, and water activities, so it may not be too interesting, and Uluru, which is the big rock in the center of the country (and not near anything else of interest). There is also wine regions in the south near Sydney, and of course nature parks to see kangaroos and the other indigenous animals.
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
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.