It's certainly possible. But it isn't possible for me, so I always play on one of the easier settings.
It's also very easy to take a wrong turn once you get to Cyseal: some of the mobs can be seriously bad news for a low-level or poorly-levelled team. I mostly work around problems like that with a sneaky character.
In general, though, moving west towards the lighthouse should be do-able, whereas moving east towards the church can get you pwned in pretty short order.
