But $3000 in 1977 is worth more than $15,000 in 2021

You look a horse in the mouth to determine age, health and what the horse has been eating.

Convert the crypto to ARRR
tell the Infernal Revolting Syndicate that you lost your Trezor in a freak boating accident while visiting your cousin, nephew, best friend...

Make a corporation. (trust)
Give it some of your crypto.
Get your sister (or other relative) to give the corporation their house.
Have corporation pay off the mortgage.