It's not just the passage of time that's problematic, lately the story has just been riddled with contrivance and cliche. The plan to capture a wight to show Cersei was really, really questionable in the first place. Dany is the one who really needed convincing, and if she trusted Jon enough to send Jorah on a suicide mission then why wouldn't she just take fortnight to do some scouting on Drogon, and maybe even snatch up a wight if she found one isolated from the horde? Yeah, her advisors would've cried about how she shouldn't put herself at risk, but they didn't even discuss the possibility, did they? And the plan they ended up going with meant Dany risking a potential key ally/vassal in Jon Snow as well as Jorah Mormont who is probably her most qualified military advisor (especially now that Grey Worm is out of pocket).
And then in this episode unlikely event after unlikely event let them succeed in the mission (albeit with some fairly expected casualties).
I've seen this season described as being like a fan fiction I think that's apt. It's giving the viewers a lot of what we've been wanting and anticipating, but the writing and story telling is not nearly as coherent or sharp as it could be.