Bitcoin core setup how to prune without downloading?
Yes you can run in prune mode, set prune=550 (or a number >=550, which is a size in MB). As blocks are downloaded others will be pruned to free up space as needed so you'll be fine with 17GB.

You can set the prune values in bitcoin.conf or as a startup parameter.

More details here https://coinguides.org/bitcoin-blockchain-pruning/