They are not the same, in fact, they have very different meanings.

冬にしては暖かいね。 - For winter, it's pretty warm.
冬にしても寒いね。 - Even for winter, it's cold.

にしては is something that is opposite your expectations, にしても is something that goes beyond your expectations (but not opposite). 

I'm not sure about that second にしても there; it's more common in the other forms (にせよ etc.)

I think the difference between にしては and いしても has been handled.

However, I don't think it's smart to unify the standalone にしても entry into the にせよ entry. I don't know a rule for it, but there's a lot of phrases that will use one over the other.

You are more likely to find 夏にしても暑い and more likely to find 外も内も同じです。どちらにせよ暑いです。 That is, Xにしても is more likely to be 'even for X' and Xにせよ is more likely to be 'whether or not X' or just, well 'Xever' for a question word X (eg, whatever/whichever/whoever/whenever ).

It's not that you can't find the reverse to some extent and not that there isn't overlap in meaning, but I don't think it does anyone a service to combine terms that are not purely interchangeable into a single grammar point, because they aren't the same grammar point.

I'd take にしても out of the いせよ　point and make it a 'related term' rather than combine the two into one.　

I can't say I'm familiar with にしろ enough to say if it's really interchangeable with にせよ or にしても, though it looks like it might be にせよ.

I know nothing about にせもよ at all... I've never seen that one that I can recall. Is it a typo for にもせよ for which you have two examples?