By a mistake from the Belgian Post Service, my Caladiums got lost and eventually were found but arrived very late.
They got instantly potted up at their arrival on 12 July., and took off quickly, showing their noses above the soil, but at the best it will still take a couple of weeks ,I guess, before they will be truly going, we will be mid-August by then, meaning their growing season will be short, around the end of September it usually gets chilly and wet, a combination Caladiums, we all know, don’t like,
I am anxious to get them growing again next season, but will the bulbs have been building up enough strength for that? Maybe if I take them inside and have them growing another month or two?
Has anyone experience with too late planting of Caladiums for their zone?

Yes, Myriam although as you know we have great conditions for Caladiums here. I won a box of Caladium bulbs in the photo contest a couple of years ago and they arrived here in August. I debated keeping them until spring indoors in the a/c so they would be cool and dry. But then consulted Bill Kurek the Caladiums For Less guy and he said to go ahead and plant them. They were beautiful for nearly 4 months, well into December for me that year, even with some very cool nights and came back the next summer rather late as well. So I had my regular Caladiums that started up in Spring, and now I have a dependable second "show" in the fall which is great.

What I'd do in your case is yes, plan to bring them into the house if you have a bright indirect light spot for them. In other words, keep them going as long as you possibly can to make big new bulbs. I'd say 3 months growing is about the least you could go for. Also right now while they are in their maximum growth and your weather is warm, water and fertilize like crazy (but I'm sure you are). They're pretty resilient plants, and I'm sure you'll get at least some good bulbs for next year.

Thanks for the heads-up Elaine!
I got the bulbs from Bill, Caladiums 4 less! They are the Jumbo sized bulbs, they are huge! so maybe because of their big size that will even be more likely for them to return next year..
Most of them are now in the stage of unfolding their first leaves, happy for that!
Glad to hear that in your case they even continued their show for a while when the nights got very cool in December.

Glad to help, but just so you know, what I call "cool" is anything below 50deg. F . . . about 10 C. Let's hope you have a long, warm fall season.

Thanks for clarifying what "cool" means in your zone Elaine, I had been wondering about that and I got it about right!