This protection exists specifically because Saskatchewan treats the family home differently from other property, regardless of whose name is registered at Information Services Corporation. A lawyer cannot complete the transfer without the required signature, so the sale simply cannot close without it.
If your spouse is unwilling to sign, the usual path is through the courts rather than around them, since a lawyer or the Court of King's Bench can address a refusal within the broader separation proceedings under The Family Property Act.
Trying to sell around a required signature only delays the sale further. Get your hand-reviewed valuation from Joel Dyck.