It depends on what you consider a championship.
A Coastal title? He could’ve probably done it this year, and if not in year 1 then definitely in year 2.
Beating UGA? Eeeesh. Given the current climate I’m not sure how feasible it would be to beat UGA more than occasionally. I think in year 3 he might could take down the beasts for the first time, but winning 1 out 3 for the foreseeable future would be extremely commendable.
An ACC Championship? Given the down year of Clemson along side FSU and Louisville struggling, he might could’ve won the ACC this year. But I think Clemson will return to being a 10+ win team so I’m sure there would be some battles there over the course of 5 years. I think in the first 5 years of Saban Tech would win the Coastal at least 3 of those years, so there would be plenty of opportunity in Charlotte
A NY6 game? Well once again, I think there would be plenty of opportunity. It would depend on matchups and who gets left out of the CFP. I think by year 3 we’d be a semi-regular NY6 team. Going 10-2 in the regular seasons and getting a shot in the ACCCG would get it us in. By year 3 we could be on the level of Wisconsin or Washington who average a NY6 game every other year or so.
A national title? I’m not sure this would ever be entirely feasible. If so it wouldn’t even be considered until about year 8. Remember it took Saban until year 4 at LSU to win a share of the title, and year 3 at Alabama. If we assume the Saban we got time traveled from 2007 without any of the prestige he got at Alabama it would still take him quite a while to build up the reputation and resources he’s had elsewhere.
If Saban were at Tech I think the program would rise very similarly to how Clemson rose with Dabo. The only difference would be that the ACC is much weaker now than it was when Dabo took over, so I think his path to the top of the ACC would happen a little faster. It took Dabo 7.5 years to compete for a natty at Clemson, and 8.5 to win one. It would really depend on how much he could change the narrative about GT, nationally and especially in state. His winning would certainly build a stronger fan base, and a stronger fan base leads to additional resources.