Is this a realistic travel plan?

Hi all,

I’m planning on leaving my job early next year and taking 9-12 months off to go travelling through south east Asia, leaving around Feb/March time)

I’m just in the process of making some initial planning, obviously it’s quite far away and this is by no means a finished itinerary. I’ve just written a draft based on places I’ve been recommended by friends and things I’ve seen online.

I’m fully expecting everything to change, but is what I’ve got down already below somewhat realistic in terms of logistics, timings, cost, etc? I really have no idea what I’m doing so any advice is very much welcome haha.

1. Fly from London to Bangkok - 1 week
   
2. Head into North Thailand (Chang Mai, Pai Chang Rai) - 5 weeks
   
3. Cross over into Laos (Luang Prabang, VanVieng) - 2 weeks
   
4. Down into Vietnam (Ho Chi Min, Hanoi, Hoi an, Ha Giang Loop) - 4 weeks
   
5. Fly over to Sri Lanka (Sigiriya, Kandy, Hortain plains, Ella, Colombo) - 5 weeks
   
6. Fly back to South Thailand (Phuket, Koh Samui, Phi Phi islands, Khao Sok, Krabi) - 5 weeks
   
7. Over to Malaysia (Kuala lumpa, Tasman national park) - 2/3 weeks
   
8. Then Indonesia (Jakarta, Bali, Java) - 4 weeks
   
9. Fly over to the Philippines (Manila, Palawan (Coron + Elnido), Cebu) - 3 weeks
   
10. Over to Australia and working my way up the east coast (Melbourne, Sydney, Byron bay, Gold Coast, Brisbane, Noosaville, Rainbow beach, Kgari, Whitsundays, Edmondson) - 8 weeks
    
11. Then to southern New Zealand (Invercargill, Stewart island, Caroline Peak, Te Anau, Queenstown, Wanaka, Mount cook, Twizel, Lake Tekapo, Christchurch, Blenheim, Wellington, Taupo, Coromandel, Whangarei, Auckland) - 8 weeks
    
12. Fly back to London from north New Zealand

Of course I’m perfectly happy to just play things by ear when I’m out there and mix things up as I go along, but I just want to have a basic plan ready.

Also how much roughly would a trip like this be expected to cost? I’m thinking close to £20k but I have no clue really what to expect.

Cheers!