Thanks GretaRSB! That makes sense. And our plans are not urgent so we won’t qualify for DCF.
We were planning to wait a few years; however, the IRS recently lost my wife’s passport with her B1/B2 US tourist visa so we are now forced to reapply for that. And, currently in Canada it takes longer to get an appointment for a tourist visa interview at a U.S. Consulate than the entire green card process. So we figure we might just go down the immigration path now since we eventually plan to move to the U.S.