I think upgrading your one VPS would be the better choice rather than having two VPS.
One thing that I noticed is you're still using Ubuntu 20, so as long as all of your software supports it, I would recommend upgrading to Ubuntu 22 in addition to the hardware upgrades. We've had a lot of people run into issues trying to update 20 to 22 on their own so we recommend backing up everything, and then wiping the VPS and installing Ubuntu 22 directly.
If that all sounds good to you here is the link to set up a new subscription https://heliohost.org/vps/pay/?code=z5fparWIrV4z5ImA and let us know when you have taken a full backup of everything and are ready to go.