For an owner-occupier buyer, an early possession date is usually more attractive than a delayed one, since most are trying to move on a schedule of their own, so a rent-back can actually narrow your buyer pool rather than widen it in a market the Saskatchewan REALTORS Association puts at 1.63 months of supply.
Where it works well is when you need to sell now but are not ready to move, commonly a downsizer waiting on a next home, and an investor buyer is willing to accept a delayed possession in exchange for a firm deal today.
Whether this helps depends entirely on who your likely buyer is, which is worth confirming before building it into your offer strategy. Get your hand-reviewed valuation from Joel Dyck.