As a swing trader myself, how many pairs should I trade to avoid these month-long zero-opportunity periods? Or should I just be patient and make no money during these periods?
Back test the same strategy on a smaller time frame. It’s wise to have at least 2 trading strategies. One for trending markets and on for ranging and/or consolidating/flat markets.
I would look at another major pair and demo test it inside a demo account, this way you get the measure of how that pair moves. You mention ranging market price, there are strategies on how you could trade them on Baby Pips and the internet. I would add my research into a my journal and write up on results from my demo testing.
This is why, I use multiple trading styles in my trading! Basically, swing trading it’s a long time trading style! So, you may not get enough number of entry points if you rely on limited number of trading pair!