Start with the constraint you cannot change. A downsizing move driven by retirement, health or an estate has a real deadline attached, and that deadline should set the schedule before market timing gets a vote, since a house that sits unsold past your own deadline creates its own cost.
Then look at condition. A house with deferred repairs or an unpermitted improvement needs more lead time to address before listing than a well-maintained one, and a home inspection, typically $400 to $600, is the cheapest way to find out what that lead time actually needs to cover.
Once your own deadline and the house's readiness are both clear, the market data tells you how to price and market it, not whether to sell. Get your hand-reviewed valuation from Joel Dyck.