There's a massive range of quality and prices when it comes to hotels in Bangkok, and the city is enormous as well, so you really want to do your research for this place. Most people are happier paying a bit more to stay near the river and all the tourist attractions, or even in the infamous Khosan Road backpacker district, which is cheap and fun, if tacky.
In addition to the obvious perks of pleasant weather and fewer tourists, off-season rates at accommodations are abundant. Voted No. 1 continental U.S. island by Travel + Leisure readers for the third time in 2018, Hilton Head has much to offer visitors. One of the most popular activities, perfect with autumn temperatures, is biking on the more than 60 miles of pathways covering the island, including along 12 miles of beaches. Bird watchers will keep busy spotting egrets, sandpipers, wood storks, sea gulls, pelicans, and ospreys. Well known as a golfer’s paradise, the Hilton Head Island area boasts more than 33 courses.
My other two suggestions are San Juan, Puerto Rico and Cartagena, Colombia. Both cities have really wonderful colonial districts and modern resort districts nearby. San Juan is more expensive, but still reasonable, and it has far better beaches. Both have a bit of rain in November, but it tends to come and go quickly. You’ll get similar rainstorms in most of the Caribbean in November, so it’s a bit tricky. I hope this helps. If you had something else in mind let me know and I’ll try again. -Roger
Since you’ve been to several of the top places in Asia already, and you love it, I think Bali might be your best bet. As I’ve written many times recently, I feel that the main tourist area of Kuta/Legian/Seminyak is just too crowded and overdeveloped to recommend, although it is interesting for a couple days and some nightlife. The arts and crafts town of Ubud is still nice, although also a bit crowded, but it’s not anything like a city so I still think you’d enjoy it.
Rio is probably the most beautiful city in the world as far as the setting is concerned, but it’s also famous for petty crime. As you mentioned, I think it’s quite easy to stay safe as long as you are aware of the situation. The biggest problem by far is tourists getting robbed by someone holding a knife or sometimes a gun, and they are often in groups. However, this almost always happens to people who are walking close to the water on the beaches after the crowds have gone for the day. The sidewalks along Copacabana and Ipanema are brightly lit and safe, but there is a mound of sand between the sidewalk and the water, so if you go to the water you can’t be seen by the security guards and police on the street. As long as you avoid that, and any other situation where you are alone in a dark place late at night, you’ll be fine.
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.