How long before we can get a line of credit against our Bitcoin

I feel like Bitcoin will be the ultimate collateral for the buy borrow and die strategy.

Say we continue with at least 20% returns annually, you could live indefinitely off of a percentage of your stack and avoid ever having to pay taxes.

I really liked Unchained loan where it goes into a multi-sig address and a third party holds the other key.

A line of credit backed by Bitcoin in a multisig by reputable company is my dream product.