Folding the best hand

You are in the final stages of a large MTT online. There are 40 or so players left. You are 2nd chip leader and have about 3 times the average stack. The blinds are very low in comparison to the average stack. You are a decent player and can build your stack well against the smaller stacks.. You fancy your chances of getting to the final table where the real money starts.

The CL is at your table.

You raise a small amount (say 3% of your stack), and the CL moves all in. Hypothetically speaking, if you know your hand has a 70% chance against the CL's hand do you risk your tournament life on this hand or do you fold and continue to build your stack slowly against the lower stacks?

If you call, at what point do you fold? When you have a 60% chance of winning the pot, when it's a 50-50?

If you fold, what edge would you need against the CL to call? 75%, 80%, 85%?