Sorry to hear the appeal was dismissed.
I realise that it's important to convince the IO that your relationship is genuine, as it's the only way you are going to get approval for him to join you in Canada. With that said, though, I would say it's more important to consider how you will make a life together in Ghana since you are have decided to go there to live with him.
Things like, will you be able to work? If not, how will you support yourselves on his salary and any savings you have? What about your obligations in Canada, how will you care for those while living abroad? These are the mundane concerns of living abroad for any length of time, not just for however long it takes to convince an IO that your relationship is genuine.
From my own experience, when my husband came to Jamaica to live with me last year, all these things came up. We discussed how the bills would be paid, who would do what in the house, what actions we would take to ensure he maintained legal status in Jamaica (non-Jamaicans are only being allowed to enter the country for 3 months at a time, we have to file and pay for extensions after that). Things like who would care for his dog (no-one, he ended up having to sell the animal), who would pay his bills and collect his mail (his father), all had to be sorted before he left Canada.
Now that his father is deceased, we have to go through all those discussions again every time he comes to Jamaica to visit. Of necessity, he can no longer spend extended periods with me, so we decided on shorter but more frequent trips, say two weeks every four months months.
I'm saying all of this to say...if you're going to go live with your husband abroad because it's the only way you can be together as a family, IMHO you should approach it from a practical, living-our-life-as-best-we-can perspective, and not from an Immigration perspective. It's impossible to put a timeframe on how long you can live with him in Ghana without considering all these things. Your circumstances will determine how long you can live together, not your need to convince an IO. There is no point in my saying, live with him for a year at least, if that is entirely beyond your circumstances.
I do wish you both all the best in working something out so you can be together as a family.