I don't expect a lot of difference, for several reasons:
1. Dalton isn't that far from Dak, skill-wise, better at some things, worse at others, but it's not like Dak ran a 4.4 and Dalton a 4.8, or that Dak had an exceptionally strong arm and Dalton can't throw the ball past 25 yards, e.g.
2. Dalton's not the entire offense, can't start rearranging all the o-line gaps, keep Zeke in to block every play, or create tons of new plays mid-season.
3. Dalton's has more experience than Dak, even after 4 years I suspect most quarterbacks are still learning some things. He's no Brady, who's "seen it all" in his career, but 144 games is a lot of time on the field. He can handle the plays, and most teams use a lot of similar routes and formations, no NFL team is totally unique in that regard.
4. Zeke's had 22 carries twice this year, 19 once, so it's not like he's only been getting 10 carries a game and will suddenly get 25 per game that from now on. He'd have to get 30 carries to get way more than he's already gotten this year, and with this poor defense I seriously doubt that the Cowboys can get to "ground and pound" mode, or a big lead.
5. Dalton's been here since camp, he's had time to learn a good bit of the offense/
6. Cooper, Gallup and Lamb can make plays on their own in part, a bad throw or such and they can "make up" for it. Lord knows they've had to do it with Dak more than a few times.
No doubt if you watch it closely you will be able to see some differences, but I'll be very surprised if we see dramatic changes.