Hi Kim, I don't (at the moment) agree with either of your suggestions, but that might just be because we haven't been given anywhere near enough information to even hazard a guess at the answer you require.
How did that conversation 'just over a year ago' start? How long was it since you had last been intimate, had you just tried to initiate intimacy and she told you "no" for the first time, had you been trying to be intimate with her for a few days/weeks/months but she kept on making excuses to not be intimate? Have you always had a demonstratively loving relationship together eg hugs, kisses, handholding, snuggling, and that tailed off recently, months ago, years ago, or have you never had that sort of relationship, and your shared intimacy only ever happened in bed, and mainly just leading to the actual sexual act? I know these all sound like very personal questions, but then you have given us your very personal predicament, and remember, we don't know you or your wife, which is of course one of the best aspects of Mumsnet.
At 61, your wife has almost certainly been through the menopause, do you know when her periods stopped completely, do you know how long she suffered from perimenopausal symptoms, do you know if she had any particular difficult symptoms during that time, and do you know has she suffered from any menopausal or post menopausal symptoms eg vaginal dryness, awful nightsweats, feeling depressed? If so, did she ever go to her GP about them, and has she been put on HRT, if she was, is she still taking them, or come off them recently? I am reasonably sure that you know where I am going with all these questions, but if you don't, and especially if you don't the answer to most of my questions, then you probably have your answer right there.
However, if your DW has been able to discuss any of these potential problems with you, and you have both had a loving relationship until about a year ago, then what did your DW say when you asked her why she felt that she was no longer 'in love' with you, and why (as she does still love you) she no longer wanted to be intimate with you? Loving a partner after decades of being together will almost definitely lead to a change in that loving relstionship. At the start it is all new and exciting, with lots of learning things about each other, and what makes each other tick - holistically, not just sexually. I loved the growth from the "in love" stage with my DH, to the other (IMO) much deeper and stronger love, of knowing each other inside out, caring about each other, knowing what we can do for our partner (both sexually and in every day life) to make our partner feel both desired and cherished. Did your feelings for your DW develope into those deeper feelings, and do you think that your DW developed those deeper feelings for you? If you think yes to both those questions, when do you think it started changing for your DW, again the easiest suggestion is could it be around the start of her perimenopause, or has she developed a chronic illness at any time, or had any big family problems with either her or your parents, or with any children? If you have children, have any of them left home, and if so, could this have initiated your DW change in thinking? Has anything in the last 5 to 10 years happened that you think may have made your DW start to reassess her life? I am female and in my 60's, and since our children have grown up and not needed such immediate attention, eg running to me for a hug, magic cream and a plaster for a bloody knee after a fall, and after my menopause culminated when I was 55, and therefore changed me into a crone (not an insult, just a fact) from being a mother of young children to what some would consider a wise woman (although I am not trying to claim such wisdom here!), I have done an awful lot of internal contemplation. Luckily (for me - I can't speak for my DH!) I still love my DH very much and want to be with him until the day I die, but the last 15 odd years have been a massive long and slow shock to the system, and I think it would be very understandable if some people reassess their lives and find that they don't want what they have had for all those years previously. I think that it is very sad for a couple (family) if one of them no longer wants what they have, but the other still does.
If your DW has not been able to explain to you satisfactorally why she no longer wants an intimate relationship with you, have you or your DW thought about going for Counselling together? Does she know how much you are missing the intimate side of your relationship, would there be any chance of you two starting 'dating' again, with both of you trying to bring excitement back into your relationship?
I just think that you should both try to explore saving your partnership - if you both want that - before seperating and trying to start from scratch all over again? If your DW definitely doesn't want to rekindle lost feelings, but you do want to (understandably) have a loving and intimate relationship, then yes, it looks like you will have to leave and set up a new home somewhere else, and try to find a loving partner to spend the rest of your - hopefully long - life with. Good luck OP.