2 Internet Services for One Home/Address

So I come from a family of 8-10 people and we all live in the same home. All of us have our own rooms including myself and 3 of my siblings who share a basement together. Everyone in our house has their own phone and for the most part, their own TV. All together there are 8-10 phones, 5 smart TV's, 3 work-from-home systems, and 4-5 gaming consoles. Every single one of these devices are connected to one modem. The plan that we're on is the Gigabit Internet Plan w/ download speeds up to 1200 Mbps. However, unfortunately all the devices downstairs in the basement have extremely weak connections. 

I, for one, have no choice but to work from home (downstairs in my room) and because of the inconsistent / unreliable internet connection, it affects me at work. Sometimes, I'm not able to clock into work on-time because the connection in my room is far too weak. Other times, I'll be working and my internet will completely disconnect on my system, leaving my boss to ask me what's going on. I've even tried using the XFI Gen 2 pods in my room and connecting my systems to the internet via ethernet cable, but my XFI pod disconnects from the internet EVERYDAY because like I said... our connection is weak down here. So, those are out of the question.

With that being said... is it possible for me to pay for another plan here at my house? I want everyone upstairs to keep the service we're all on now, but I want a separate service to run downstairs for us here in the basement. I think it's worth pointing out that me and my siblings, who are downstairs, have our own kitchen, bathroom, laundry room, etc. so it could pass as a separate home. I want it to where we have a separate

Gigabit Internet Plan (1200 Mbps) and our own modem from the plan and modem upstairs (hope that makes sense).

I've read multiple reviews and Xfinity doesn't seem to be consistent with the information they're giving out to their customers. I hate calling them because they never help me fix my issues and most of the time, their representatives don't always seem to know what they're doing. Depending on who you speak to, the information you receive from one agent contradicts what another agent tells you. So it just leaves me with more questions.

So I guess, I just wanna ask if anyone currently has 2 services running at their home and if so, how?