As one slave driver to another, I don't see what dealing with people accomplishes. But, it's your call. Give me the names and times. I'll have them check in at the security office and send a member of patrol with them. I'll have patrol return at the end of such time as you designate to escort them back to the castle.
As it happens, there are quite a few single beds left in the dormitories. House elves will deliver them in an hour. Along with a fair number of blankets, including extras just in case.
The double was a little more difficult to procur. However, Lupin was able to inform me of a suitible four poster. It's done in Ravenclaw blue, which may not suit your Gryffindor sensibilities. However, with then number of pillows and coverlettes, you and Cal should be quite comfortable.