Rsvps came back “declined” with money

We sent out our invites and we’ve received 2 so far marked “declines with regret” and check: cash included along with handwritten notes on the back of our RSVP card. I have a few questions and I am not certain how etiquette would apply.


1) How soon should we write thank you cards? My hubby said wait till after the wedding which is still 8 weeks away when we write all the thank yous. I suggested a week or two after we received their declines since I don’t want to cash a check and not write a thank you right away. Thoughts on this?
2) Just for peace of mind, is this the standard for declining and sending cash/ check with a note on the RSVP cards or were these exceptions? I always thought you should still send a wedding/ congrats card with a note and cash/ check if not attending. That’s what we did when we couldn’t attend a wedding a few years ago. We marked “declines” and sent back and then timed out a wedding/ congrats card right around the time of the wedding. I was surprised to see wishes being written on the back of our rsvp card. Isn’t it a bit tacky not to just send a separate card?