I have used this for shoes that had a "Nubuck" finish. Kinda like suede, I guess. I'd be nervous spraying it on suede. Maybe test a hidden area first and see how it comes out?
They're waterproof, just on the wrong side ... <G>
Mink oil is great for darker suede as long as you apply it properly. Trick is to put it on liberally using a shoe rag with a circular motion THEN immediately blot off as much of the oil as possible. This step is important to restore the nap. Repeat as necessary.
Lighter shades, maybe not? And blue suede? Yer on yer own there, but I'd suggest you'd lay offa dem blue suede shoes. ;-}
Tough to waterproof suede. Top grain leather is easier to barrier with something like Sno Seal or similar. Most suede that needs to be proofed would instead need a Gortex liner. Any effective proofing material you might apply will change the look and texture of suede. There are sprays that will do OK for keeping snow from melting and penetrating but they will not be truly waterproof and take a dunking.
Is your sole peeling away from the suede on the right boot? That's a source for a leak.