Just did it this weekend from Winchester to Polgate (Eastbourne train station was closed) on a gravel bike (650B x 42c).
We were a bunch of people with all kinds of different bikes. Everybody made it but everybody also struggled in their own way so a cx should be fine. I guess doing it all in one go is quite a challenge though. There are some serious climbs and even if you are a good climber it just takes a lot of time. We did in one full and two "half" days which was really nice but two days should be doable if you have less time and the stamina. There are a few train stations close to the route if you don't make it or want to start further down the route.
In any case it's totally worth it.
Just did it this weekend from Winchester to Polgate (Eastbourne train station was closed) on a gravel bike (650B x 42c).
We were a bunch of people with all kinds of different bikes. Everybody made it but everybody also struggled in their own way so a cx should be fine. I guess doing it all in one go is quite a challenge though. There are some serious climbs and even if you are a good climber it just takes a lot of time. We did in one full and two "half" days which was really nice but two days should be doable if you have less time and the stamina. There are a few train stations close to the route if you don't make it or want to start further down the route.
In any case it's totally worth it.