Half Year backpacking trip through North America and South America - Group Travel

I'm a 30 year old guy from Singapore and I plan to fly into Canada and hopefully spend a month or less there. Thereafter I hope to go to Alaska whereby I can do some voluntary work to offset my lodgings and food. It would be ideal if I can spend 1 month in Alaska. Key highlights would be to see the Aurora and also do some snow sledding if possible. Thereafter I would start at the top of the west coast of USA and maybe do some voluntary work in the national trails to offset lodgings and have some exposure to the wilderness. As I travel down, I would be visiting the various cities. Once I hit the bottom of west coast, I would likely fly to northern part of east coast and make my way through all the cities. And finally departing USA into Mexico before going further south into South America. Likely to spend a total of 4 months or so in north america and maybe another 3 months more in South America. Currently my plans are to travel alone but I would be glad to have a travel partner too!

Half Year backpacking trip through North America and South America