Right. However get the priv. keys from the seed isn't easy at all.. with electrum I imported the seed and got balance but can't export priv. keys.
It's actually pretty easy.
You just need to restore a wallet with your Trezor/Ledger seed and check "BIP39 seed" in Electrum. It will generate your hardware wallet addresses. Then, just go to the Addresses tab, right click the address and select "Private-key".
In Electrum: "Standard Wallet" -> "I already have a seed" -> Write your seed -> "Options" -> "BIP39 seed" -> Next.