3 bed 1st floor council flat with rtb swap for 2/1 ground floor property with own garden

Hi, I am looking for a mutual Council or Housing Association exchange. I have a secure tenancy (with Right To Buy) 3 bedroom 1st floor Council flat in SE23 that I would like to swap for a secure or assured tenancy 2 bedroomed (maybe 1 bed if it’s exceptional and “ticks all my boxes”) bungalow, house, ground floor maisonette or flat with own private, secure garden.
I do not need the RTB but tenancy MUST be either secure or assured, MUST allow pets AND have a garden for own use.
I would stay local/in London or the South-East for the next few years IF “the perfect place” were to come along but my ultimate aim is to retire to Edinburgh/local areas within say, 20 miles. As my years have grown, along with my sons, who have (mostly) moved on, I wish to downsize and, hopefully, relocate.
If you are renting your home from a Council or Housing Association, need a bigger property, or know someone who does and if you/they have what I want, these are the areas I am interested in: Edinburgh/surrounding areas, some areas of Southeast London, South Croydon/surrounding rural areas or South-East Kent/Thanet areas. Also, I will look at & might consider other properties that are not ground level, only 1 bedroom & maybe further afield. Open to suggestions but NOT interested in Central, North, East or West London at all nor most of Croydon borough.
I belong to some mutual Home Exchange sites and am constantly looking at adverts but thought I would place one here just in case someone else might be looking or know someone else who is. Thank you for reading. Regards, Sue