Etiquette experts,please help.

[Mirage]

We have been invited to a drinks do at a local stately home.We have been sent a very formal invitation & I am struggling to compose a reply.

If it helps,the invite is as follows.
Mr& Mrs XXXXXX,have pleasure in inviting Mr & Mrs XXXX,for drinks at xxxxxxxxx,on xxxxxxx.

Thanks for any guidance-I don't ever go to things like this & don't want to make a fool of myself.

odes it ask you to RSVP?

mr and mrs xxxxx are pleased to accept the invitation for drinks at , on

Debretts says

If you are sent a formal invitation, you should send a formal reply, written by hand, in ink, on headed paper and in the third person: "Lady Clackhorn thanks Mr and Mrs John Sexton for their kind invitation to dinner on Thursday 15th January and has much pleasure in accepting". or "Lady Clackhorn thanks Mr and Mrs John Sexton for their kind invitation to dinner on Thursday 15th January, but due to a previous engagement she regrets she is unable to accept".

Mr & Mrs xxxxxxxxx
have great pleasure in accepting your invitation
to

I think you just say that Mr and Mrs X will be delighted to attend (or that you will be unable to attend), but someone posh will be along soon, I expect.

The rule is to follow the wording of the invitation. So say 'Mr and Mrs XXX would be delighted to come for drinks at XXXX on XXXX'

Wow-that was quick.It does say RSVP & gives an email address to respond to,or a phone number.I am planning to email as I will probably start stuttering or rambling if I ring up,plus I won't know whether it is Mr & Mrs xxxx or their secretary on the other end.

There is one other thing,Mrs xxxx is quite famous & well known under her maiden name,but,on the invitation,uses her married name.If I have to do any introductions,which name would be correct for me to use?

Ohh this is a minefield.

If she sent her invitation under her married name, Id use that.

lol at an email reply in the third person! I think that is unknown territory, so maybe some more opinions are called for.

I think Id chicken out and write a reply (with a Parker fountain pen of course ) and post it by snail mail.

Is this the poshest invitation of the season winner, girls?