Sorry can not help much but give you couple of pointers on Laos and Thailand.
1. ttp://
www.resorthotel.net/laos/hotels/luangpr ... cation.htm
I have found hotels in Laos to be moreexpensive than Thailand but you can save money if you have USD. Might be worth checking into one first and dumping luggage before talking a walk around.
2. Travel in Laos is difficult. According to the site below its is possible to do this journey in a roundabout way. It will definitely be by road and very lengthy. A very good alternative would be boat as both destinations are on the Mekong. What I am not sure of at the moment is what Laos/Thai crossings are available to foreigners.
The alternative via Thailand is: back to Vien Chan, cros over bridge to Nong Khai, bus or train to Khon Kaen, bus to Pitsanalouk, bus to Sukhotai, bus to Chiang Rai. Again this is a roundabout route.
Bus fares usally work out between about .6 Baht and 1.2 Baht per KM.
http://www.resorthotel.net/laos/maps.htm
3. Many cheap hotels in Chiang Rai. Use the Lonely Planet Guide 200 up for fan room, 350 up for air-con.
4. Travel by train from Chiang Mai to Bangkok has to be the best option. Here is the timetable
http://www.railway.co.th/timetable/N_N.html
You should be able toget the fares from the same site. It all depends on train type, class and whether or not you want a sleeper. Obviously you save a night in a hotel if you use a sleeper. The last timeI did it three years ago it was 1,100 Baht one way for a 2nd class sleeper. Journey takes between 12 and 14 hours depending upon train type.
Two things to be aware off though. November is high season so book as far in advance as possible. Maybe from an agent in Chiang Rai at the same time as booking your travel to Chiang Mai. In November it can get very cold up there so you won't need air-con.
I find buses scary on mountain roads. Overtaking on blind bends and all that stuff with tired drivers. You may save a little bit of time and money though. Also buses are uncomfortable and the toilets are bad. You can not move around or eat when you want.
Another bonus of the train is that you can stop off in Ayutthaya on the way to Bangkok. Well worth seeing.
Good luck