You should find a transaction id for that unconfirmed transaction. You can look up your address that you sent the coins to or from in some block explorer like this one
https://blockexplorer.com/ (you might want to use Tor borwser for anonymity) or you might want to try to look it up in Electrum, if it offers such feature.
Getting txid will allow you to look up more details about that transaction, like the exact fee it was used, you can see more info about the transaction by putting txid in a block explorer. You can post the fee here or even txid if you don't mind the privacy complications of reveling your address publicly.
You can look up the appropriate fees on
bitcoinfees.21.co or just ask here for that fee and someone will approximate the confirmation time for you.
Don't worry even if you lost access to that old wallet as long as you have the address that the coins were sent to (the Electrum one).
You can always use CPFP method to get that transaction confirmed quickly, whenever you want.