Cable internet connection

So we moved back to the States in 2006 and we got Verizon for out phone, internet(dsl) and TV (DirecTv). After several years my wife bought an ipad, and her and our daughters all bought cell phones. In the evenings they were killing my bandwidth. I couldn't even watch a Youtube video. So I had cable installed for myself (Spectrum).

So now my wife is complaining that Verizon costs too much and she wants to switch to Spectrum. She said she wants her own account so we'll have 2 cables coming into out house. I told her they won't do that, and if they did, the 2 cables would be hooked together at the pole and she'd still be taking all the bandwidth. She said she's going to call Spectrum on Monday and tell them our situation, and what she wants.

Now I'm wondering if I only have Verizon internet, and they have Spectrum phone, internet and TV. I wonder if that would be cheaper.

So am I right when I told her they won't let us have two accounts/cables coming into our house?