It’s worth noting that Minhagei Vermeiza (p50-51) in fact says not to go to either the chupa or the seuda, but everyone quotes the minhag as talking about the chupa only. The same section of Minhagei Vermeiza also gives a lot of other minhagim that are not followed today at all.
I’ve seen weddings where the children stood behind a glass window, to see the chupa without technically being there. I’ve also seen many many second marriages where the children attended and played a significant role.
Many Rabbanim when asked will agree that the reasons do not apply in our generation, and in fact that children may be emotionally hurt (in some cases) by not attending. Also most parents nowadays do not object to their children attending a remarriage, and do not consider it a pgiya in their kavod, as long as it’s in the best interests of the children. As always a Rav must be consulted in all cases.