I would check the Terms-Of-Service.
As handsonhosting stated, if you have a domain renewal, then you seriously need to notify your host, as a lost domain can be very expensive to rectify.
Usually hosts have a grace period, this is not "free time" as this time will be taken into account when/if you do finally pay.
Beware however that hosts will charge a late fee payment if you go too far into the grace period.
It looks like your ready to cut and run, so the late fees are probably not a worry, but the suspension period probably is.
It's unclear from your post whether you are an end user or reseller, is the risk of your sites being lost worth the risk of not paying on time? (or for another month if you are cutting and running)