Small restaurant- large party cancellation charge?

Hi all- my husband and I have a small farm to table restaurant in rural Iowa. We stay pretty busy in the summer for where we are but we’re putting out city-level quality food and still hardly get by (as I know this is the same plight for all small businesses right now!). Anyways, the point of this message is that we’re sick of getting last minute large party cancellations and not being able to fill the tables. We do all our reservations and seating charts manually with paper and pencil as we’re small and are always moving tables around to make things work so relying on a reservation platform doesn’t really work for us. If you’re a small restaurant, do you charge parties over 5-6 a deposit in the event they cancel under 24 hours? We didn’t want to have to do this but are now strongly considering it. We can’t afford to lose large parties day of service. Thanks for the insight! Please be kind :)