Using SSL certificates on multiple domains on one IP address

I have a dozen or so domains on my server, they are mostly single site and then I have two multisite as well, that need SSL certificates (google rank boost). The challenge is that I only have 4 dedicated IP addresses available on my server and I use two for name servers. I would like to get my free certs from letsencrypt.org (yay Dec. 3rd!) and I have read this blog article https://premium.wpmudev.org/blog/ssl-domain-mapping/ - unfortunately comments are now closed on that article so I could not ask there.

Is this possible? To be able to install a number of certs, one for each of my domains, all on the same IP address?

Thanks in advance for any feedback or direction!

Chris