The way to pause a paid subscription to stop charges for a period of time would be to downgrade the account to the Free Plan. Downgrading the plan would involve going through the subscription cancelation process.
Some important points to keep in mind and prepare for when downgrading an account are:
The existing campaigns and contacts in the account will remain untouched, all data will be saved to the campaign and website stats, so there's no need to worry about losing data or work.
When on the Free Plan the account will only have the plan's available features. This means that active popups will be deactivated, landing pages using custom subdomains will be deactivated, and any premium features used like conditional actions will also be deactivated.
If the subscription is a legacy plan, it won't be possible to upgrade back to the same plan once it's been canceled.
The ConvertFlow install code can remain on the website and track visitors as it will deactivate when the Free Plan's limits are reached. So there's no need to worry about autoscaling.
It's still possible to use landing page campaigns with the default convertflowpages.com domain. keep in mind that some ad platforms don't allow running ads to landing pages that don't use custom domains.