Get an 8TB backup drive (Costco has them really cheap), and run Macrium Reflect to clone your HDD onto the backup drive. Macrium Reflect makes use of Volume Shadow Copy, so you can continue using your computer while it's backing things up.
Those big backup HDDs use shingled storage, so they're not any good as general purpose hard drives, but they're excellent for strictly sequential writes, such as a full disk backup to a single file.
Those big backup HDDs use shingled storage, so they're not any good as general purpose hard drives, but they're excellent for strictly sequential writes, such as a full disk backup to a single file.