It is possible on electrum, however im not sure why do you need so many addresses from one seed
Would help alot if you told us what wallet you are using, at least the following would be the procedure for electrum.
Open up console from "View" -> "Show console".
Then write the following there.
wallet.storage.put('gap_limit', 50)
wallet.storage.write()
Replace the 50 with the amount of addresses that you want, but remember that many thousand addresses can and will make your electrum very slow.
After you are done entering the commands, restart electrum and you will have many addresses there. However if you ever restore the seed on some wallet, you'll only have 50 addresses or so on as far as i know.