The food, including its famous ceviche dishes, is a particular highlight here, and the tourist district of Miraflores is packed with interesting and cheap restaurants. Basic and cheap hotels are in the same neighborhood, so it's a better alternative to the historic center of Lima for most people. By the way, the rainy season in Cusco starts in December, so the trails can sometimes be cut off, although many people go anyway.
Another consideration is that Thailand is generally easier to get to with far more flights that are often cheaper, and Thailand also has FAR more beach options because of its long southern coastline and especially the islands. The posh beach areas on Phuket are typically the most expensive beach hotels in Thailand, but there are other more remote beaches in Phuket with lower prices so it’s worth a look. Aside from Phuket you should also look at Ko Samui, Ko Pha Ngan, and Ko Phi Phi. You might also look at the town of Pattaya, which is the closest beach resort to the Bangkok Airport. Parts of town have a lot of single foreign men in certain bars at night, but most of the town is actually quite family friendly and very good value. Let me know if you have other questions. -Roger
And as you mention, Bali could actually work for you. I’ve spent two Decembers in Bali, and December is quite a bit rainier on average. Still I had a great time and it was sunny most of the days. The rain in the tropics (and Bali is almost ON the equator) tends to come down in 30-minute bursts rather than drizzling all day, so it’s usually pretty easy to avoid. The best part of Bali is there are loads of things to see and do, and the nightlife is excellent. The Kuta Beach area is fun for at least a few days, but I wouldn’t spend too much time there. You should also spend a few days in Ubud, which is very touristy but also interesting. And you could spend some time in Lovina, which is along the northern coast and it has all of the charm of Bali from 20 years ago before most of it got overbuilt. With all the temples and other local attractions, there is always something interesting to do, which is not true of many other places with great beaches and nightlife. Let me know if you have any other questions. -Roger
Oh, did you want a sunny tropical vacation that doesn’t require a passport? Done. Hurricane season is over, flights are cheap, and the water is still warm enough for swimming (and scuba diving). Almost all the tourists come here via cruise ship, which means you’re mostly not competing with them for hotel rooms -- Windward Passage, Emerald Beach, and the Bolongo are all open for business after Hurricanes Irma and Maria last year. On December 16 you can catch Jazz By The Sea down at Coral World Ocean Park, and on December 21 watch the St. Thomas Lighted Boat Parade, where contestants (boats) are judged on lights, originality, and holiday cheer.
Prices go up a bit when you go south into Malaysia, but it’s worth it if you’ve got the money. You might even consider Myanmar as well, which I’ve yet to visit, but I keep hearing great things about. It’s honestly the perfect time of year there. By April it’s insanely hot (the hottest month of the year), but December through February is lovely. It’s all quite safe as well, as long as you keep your wits about you. I’m happy to help with more information if you need it.
The rainy season in Cartagena winds down by early November, so this is an ideal time to come, especially toward the end of the month if you can get cheap airfare before and/or after Thanksgiving. The temperatures are pretty much the same here every day of the year, so the key is to work around the autumn rainy season to when it's dry but before hotels fill up.
In Vietnam every hotel will have a “tours desk” that will happily book a tour or visit to any local sight imaginable. There are also dozens of independent travel agencies around booking these same tours, but some of them are better than others. I prefer to book tours through my hotel, even if it costs a bit more, because it helps them and they have a strong incentive for you to be happy with the tour. If a hotel would consistently book guests on tours that the guests felt were rip-offs, that would be in the reviews and they would lose future business. More expensive hotels tend to charge more for the same tours, but things in Vietnam are so cheap that it’s not worth worrying about. And you might get a better pick-up at the nicer hotels as well.
Southeast Asia is easier to deal with, and there are cheap flights connecting in the Middle East and landing in Bangkok, Kuala Lumpur, and Singapore. Each of those is a very interesting city, and there are many smaller places to go in the same region. In Malaysia there is Penang and Melaka. In Thailand there is Chiang Mai and quite a few others in that area. In Laos you can visit Luang Prabang, which sounds like it could be a winner for you. And there is also Siem Reap, which is home to the amazing Angkor Wat temple complex.