Passing BTC to heirs

I have a significant amount of BTC. I hold the keys on a Trezor device. I wanted to make sure my wife could access the coins and move them to an exchange after my passing. I wrote a very detailed memo to explain to her. I then sat her down and watched her go through the memo to try to access our coins and do a test transfer to Coinbase.

It was a disaster

I am nearly certain that no matter how detailed my instructions are, there is a decent chance she will lose access to our coins. And that’s if the trezor is available and working. Forget about restoring from our seed phrase and pass phrase.

I am thinking I should just move our coins to our crypto account at Fidelity. We have an unused crypto account there and they recently began allowing deposits and withdrawals of coins.

I love self custody but I guess my fear of fidelity losing or taking our coins is less than my fear of her losing access to our coins. I’ll keep the trezor and I can always move the coins back if things get sketchy.

Any better ideas?