XP's are my favorite SP.
I would not rechamber myself either, if you intend to keep the orginal barrel on it.
But I would not hesitate to rebarrel and open up the boltface to something on the 308/30-06/284 boltface or the WSM boltface. I have had several fireballs and none of them are fireballs today and I don't have an regets.
I have had, have, or will have soon XP's in 250 Sav AI, 6mm-284, 6.5-284, 7mmBR, 7mm-08, 284 Win, 7mmWSM, 7mm Dakota, and 7.82 Patriot.
I said this to make a simple point.
You can customize an XP-100 to just about anything imaginable, and it is a stronger action and inherently more accurate than a break open action (but not as versatile).
If it was me, I would turn it into a rig that would take both varmints and deer for sure. Even know a couple of proven smiths that do all of their own work on XP's.