Wedding Invitation Envelopes

I am DIYing our invitations and realized I ordered the wrong size envelopes.

Our invitation is a 5x7 card with 2 smaller detail cards all a printed on cardstock (18pt / 400gsm).

The envelopes are closer to a A7.5 (5.4x7.6) instead of an A7. Although the invites add some thickness there is quite a large gap maybe .25-.5" total on the long edge. Is this going to mail okay, or will it just break and tear in the USPS sorting machines?

Curious if anyone has used slightly oversized envelopes (more than the normal 1/4" buffer in standard A7), and if so, did all the invites make it to your guests without getting super damaged?

I already addressed a number of them so ideally not looking to order something else, and I wasn't planning on doing an inner outer envelope combination type of thing.

Thanks!