I have same opinion with you, Oda really sucks in giving timeline with One Piece. But I think the adventure will not be rushed, I think it would take more than 5 years but less than 10 years to end.

I think after Wano ark, the strawhats would be heading to the final arc which would be Raftel. Might have a little detour in Elbaf but I do not think it would be an arc with hundreds of episodes. It might be like the islands of the Mink tribe since I do not expect long battles in it giving the thoughts of them befriending 5 giants already. Might have a detour in there because of the 4th rio to pinpoint the location of raftel.

So i think after Wano, the final arc would more likely to starts.