we'll cross that bridge when we come to it...

To deal with a situation when, and not before, it occurs.

For example, If we can't sell the housewell, we'll cross that bridge when we come to it.

The ultimate origin of this proverb, a caution not to anticipate trouble and often put as ,has been lost. The earliest recorded use is in Henry Wadsworth Longfellow's The Golden Legend(1851): "Don't cross the bridge till you come to it, is a proverb old and of excellent wit."

Stargate fans might recognise this:

Teal'c: If we are caught, you will be brought before Apophis along with us.

Col. O'Neill: We'll cross that bridge when we come to it.

Bra'tac: No. The bridge is too well guarded.

Col. O'Neill: Here's the plan----------

Watch this hilarious crossing the bridge video :~))