I am thinking if it would be possible to run some Linux distribution with GUI from USB stick, install Electrum wallet on this OS to generate keys and seed words and backing everything up until needed.
It is possible, of course. It would be even better if you decided to use a separate laptop without Internet connection on which you could store your encrypted private keys and sign transactions. If you are not going to send your bitcoins often then you will be fine with simply generating your wallet with live CD operating system, encrypting it (doing it either in Electrum or using a third party app such as VeraCrypt) and store on multiple devices in case one fails.