Regarding 1 Cor 3:15.
I have seen some Catholics refer to these verses as Scriptural proof for the concept of Purgatory.
Whether you agree with that or not, reward and salvation are used interchangeably in the passage. I don't see "going to heaven, but receiving a lesser reward". Purgatory is a better fit for the passage.
Brother in Christ
I don't beleive there's any scriptural proof of purgatory. It's only through reaching translations and reaching logic that you get purgatory.