I think it's totally valid to be in a stage where you have to move fast, as long as you understand the size of the technical debt that you are incurring. Don't ignore tests blindingly though - there are definitely pieces of code where writing tests will actually help you write faster (TDD or not).
Writing code that is easy to test will improve reliability even without actually writing tests, as the principles that make code testable are the same for writing good code (very modular, declare dependencies, single responsibility etc.). So I would suggest doing that.
You can also invest time in monitoring. If your mean time to fix is good, it balances out the time you put in testing... though this method won't save you time probably.