If your not in a hurry watch ebay or craiglist for canti cross frames or bikes, brand new ones pop up cheap because everyone wants disc these days. While my race cross bikes are disc my winter training bike for the past 4-5 years has been a canti cross bike. I use mine for gravel, mtb trails and on fast group rides on the road, even with cross gearing and file tread tires I have yet to encounter a time that I got dropped because the speed was too fast on a road group ride.
Lots of nice options in this thread. I've been riding the E5 version of the diverge for almost a year now. First real road/gravel style bike ive put a good amount of miles on (both on and offroad) and i love it. Consider the steel Specialized Sequoia for a less racier geo and more mounts for bags, fenders and such.
I've spent time on a Diverge during the Gap/C&O trip and it's an impressive bike. I ran 38s on it and they were able to handle everything I found. Commuted back and forth to work with it and it was faster on the road than my All-City.
Really hard to a rogue against a Diverge... great bike, on and off road. One of my riding buddies was on one this weekend for a 70 mile road ride and he seemed to have no trouble maintaining pace with the rest of us on regular road bikes, except for maybe the steepest of climbs.... and that was after a lot of miles in the legs. I think that maybe it was just a knock-on effect of the added weight from the bigger/treadier tires over time. Normally, on his normal road bike, he has no trouble keeping up.
If you're riding the road a lot it might be worthwhile to swap on some try road tires or a different set of wheels.