Get a dedicated solo boat or a 15/16 ' kevlar.
My solo royalx is 45 lbs and easy to carry and can hold the gear for a week, and that is shoulder seasons where it is much cooler.
Also you need to get out more and paddle. Practice and KM's under the belt will make a trip much easier.
Also paddling a solo with a double blade with make it easier also.
I only kneel when the conditions that are rough, either WW or large waves.
Any fitness program will also help, walking, bike riding, yoga/stretching.
Being out of shape or just a weekend warrior does not help too much as you age.
Here is a thread to follow up on that.
http://www.myccr.com/phpbbforum/viewtop ... 16&t=45510If you can try different solo boats, some are more stable than others.
Lots of things you can do and BTW you chose a good loop to try, it is very under-utilized and a great intro into northern paddling.
And you made a good start by asking questions, it is a great way to learn.
Jeff