The Xtherm will be fine in warmer weather (after all, you're typically laying in/on top of a sleeping bag which is warmer than the pad), and you'll be happier with the Xtherm at 5* than a less insulated pad.
But 5* isn't especially cold, so another way would be to get a Neoair Xlite, and use a full length 1/4" Evazote pad on top when it's going to be colder.
Evazote is now available again after a long spell...
https://mountainlaureldesigns.com/product/1-4-foam-pad/
