Just look at OOL...they now have DOCSIS 3 available everywhere.
If you are willing to pay them a $300 bribe to turn it on for you. This is in addition to a $35 fee to hand deliver the new DOCSIS3 Modem to you and hook it to your existent coax where you current modem is connected. I am willing to say the fee is probably justified since the visit allows the tech to test your line and verify that everything is working (something that is not possible with a self-install where they hand you the modem at a store front [or mail it to you] and you plug it in yourself). The extra $45/month (over the 30/5 Boost Tier rate) is not an issue since that pays for you getting the 101/15 tier.