Getting ready to issue IP address certificates

Is there anything public available on which IPs will be able to get certs? I mean, obviously private/reserved ranges won't be available, but how about all those "cloud" services that rent IPs by the hour (or second)? Is it expected to be "normal" that someone could release an IP back into a pool and yet still have a valid certificate for almost-a-week, or will Let's Encrypt certificates only be available for IPs that are slightly less ephemeral?