That's an idea that could work indeed .
You just gave me the idea to build simply a custom software to encrypt my Electrum seeds , making something Custom and hard to decrypt is better then use something public even if it's strong hacker will know from where to start unlike custom encryption it could make you earn sometime .
good idea
I guess the veracrypt/PGP solution is a good one too, however this relies on keeping it the cloud which gives a would be hacker a lot of time/opportunity to work at it before you would know about it.
If your seed is encrypted through PGP, then you should be safe even if a hacker has access to the encrypted file. As long as you don't store an unencrypted copy of your PGP private key in cloud storage along with your encrypted seed, you should be safe for years to come because the encryption PGP uses is so strong.