Only you can answer that really, there’s no rules. Some will say go smaller on a CX bike (I don’t agree but it seems to be road race vs CX race wisdom and I don’t race), others will say go larger for longer distance comfort (don’t fully agree with that either)
On the basis that a higher bar and a shorter stem (it’s already fairly short though) is often a good thing on a non-race all-rounder bike, you could go larger. Or, go smaller if that doesn’t sound appealing.
Also it has a 74 seat angle so when you’re out of the saddle it’ll feel more like a 73 seat angle bike with 10mm more on the ETT – ie the Reach is roomy for the ETT. That may mean the S frame isn’t as small as you thing when compared to another bike you may like the fit of. HTH.