Is our awning too big?

we have ended up with about 5cm of awning cord stuck out at the end on either side (and almost a divorce 😂)… can that be right?

I presume you mean at either end of the awning rail? That is not a lot to tightly peg it to the ground! Storm straps should not be necessary to pull an awning tight and would not normal do so, at least  they wouldn't when I had one.

The only thing I can suggest is measure your awning rail length from ground to ground by feeding a piece of string through your rail and compare the resultant measurement with the awning cord length.

Finally if you were not on level ground, it can be quite hard to make it a neat job.

peedee

Have you checked your caravan manual as ours tells us the awning size required, hopefully you can get it sorted and as Peedee said if on uneven ground it can be a bit more difficult to get it sorted.

Many, many years ago we had the reverse problem to yours!  We purchased a new awning and the dealer supplied us one to fit our little Fleetwood Colchester.  The awning was too small!  We were new to caravanning then so some helpful folks came along and measured as Peedee suggested, proving that the awning was too small.  We contacted the supplier who accepted that they had sent the wrong size and Couriered down the correct sized awning which arrived on site the next morning.  So message is  IF supplier has sent wrong size get them to exchange it.