I am amazed at the knowledge concerning canoes in this forum. It's like a lot of these guys have been to "canoe college". I can't hold a candle to them when it comes to length x width etc.etc.etc.  

What I do have is some experience with solo boats. I'm amazed at the rough water she can handle and how well one can paddle in wind. Nicely done indeed. With the weight amidship the tendency is to bob about like a cork. It's actually rather fun. Now I don't want to mislead you, I'm not going to be out trolling for lakers when it's snotty but rather easing along the bank. Polarized glasses are a big help to spot rocks.

How flexible are you? Perhaps since things aren't going off as planned something new may be in order for you. :question If you go solo my advice is to stay busy. My first solo trip was 13 days and I was going morning to night and never got lonely a bit.

I suspect that a true solo boat is likely more seaworthy than soloing a tandem. This is merely a hunch and people who really know what they are talking about will likely weigh in.
Good luck (Go for it!!)