The naivete that 60s writers had about time travel ideas showed here.... or else it was naive mainstream viewers they were writing for, not wanting them to get confused. There was never the slightest need to claim that Collinwood was somehow frozen in time during the time we saw events from 1795. That makes it sound as if 1795 was somehow happening "concurrently" with 1967, when it wasn't. It was 170 years earlier. The point of view of the viewer shifts back 170 years, along with Victoria Winters, then we experience those events, then DS shifts our point of view (and VW) back forward to 1967, or rather 1968 (a glitch we can't resolve). If months had passed in the "present", then as Lydia said, the rest of the world would start to notice the rich freaks playing at being statues... the paper boy would want to be paid and would look through the window, maybe..... and would come in and pants Roger....
We (as observers) and VW traveled back in time, then traveled forward again to the same point in time in the present (not months later). Collinwood wasn't frozen.... it didn't need to be, to explain this. It's just that viewers accustomed to "sensible", straightforward, linear stories would ask... "But what's going on at Collinwood 1967 while all this is happening in 1795?" Answer: nothing of course. Two eras aren't happening at the same time... it's only DS and its wacky storytelling methods that makes it appear that way, if you're not paying attention.
I agree that it makes no sense whatsoever to tell us that events in 1795 and 1968 were happening concurrently, but I wonder i the writers didn't intentionally sacrifice logic for the sake of setting up the sappy, drippy scene a couple of episodes later in which Spoiler:Vicki finds Peter's gravestone and learns that he died not only on the same date but at the same time of day (cue: Bum Bum BUM!).
But I've never been a fan of the Vicki/Peter/"I'll find you" story, so I could've done without both it and the setup.