Hey Bob,
From what you are describing - yes it makes sense. When our dollar is stronger against the US - it makes sense to load up on US stocks and the vice versa is also true. Given the strength of the US dollar, personally I am focusing on my CAD positions and simply using my US dividends to purchase new US positions. I usually only look to buy US stocks when our dollar gets to over 0.80 which unfortunately, hasn't happened very much over the past few years. Flirted with it briefly last year but has since weakened in a material way. When our CAD was ~1 I bought nothing but US stocks - last time this happened was in the early 2010s I believe.
Now, whether you chose to sell 2/5ths of your portfolio to move into CAD equities is entirely up to you. That said, I'd be weary of selling good stocks just for the sake of taking advantage of a lower dollar if you know what I mean. I'd personally take a good stock over the potential for exchange rate returns any day. That said, if it makes sense to be selling then putting that into CAD equities may very well make sense. We can't exactly provide firm directions in this area because everyone's portfolio is different, but the general concepts of what you are talking about does make sense.
Mat