Where to put some leeks!?

My local garden centre just opened up some click and collect orders so whilst ordering some compost I noticed they had trays of leeks available. I dont really have the space, but bought two trays of "joliant" leek. They are currently in small module trays and are about 15 cm's tall but thinner than a pencil.

The only bit of space I have is in a raised parsnip bed, which is just all multi purpose compost.  Can I plant each leek here until one of the main beds is available?  At what time would I take the leeks from the raised bed and plant in another to get them bigger for winter harvesting?

Thanks.

Perfect. Thanks. I'll aim for that time then.