It's advisable to delist all items when you go on holiday and not able to post on time.
If there is no one who can post the item for you, you could face negative feedback ,case for item not received and account defects.
You could send the buyer a message explain the delay, but you would still face a late delivery defect.
You still have items for sale I strongly recommend ending them then they will stay on your My eBay for 60 days and 90 days if you are on the Seller Hub in your unsold listing. Relist them for sale on you return from holiday.
Or take a look at Time Away here:
https://www.ebay.co.uk/help/selling/selling-tools/time-away?id=5137&st=3&pos=1&query=Time%20Away&int....
@tinotops
