I recycycled some clothes that had been sitting on the doorstep in a plastic bag. They were dd's bagged up since a year ago, shameful that they didn't leave the house earlier..it took a fox trying to rip the bag to make me act.
toomuchtupper I have dealt with a few mice in my time (cat leaves them on the floor in bits [eugh] but I know how you feel...I take my glasses off to deal with them and feel quite odd afterwards. I think living with three cats has made me more insensitive 
I am also struggling with laundry, perpetually. It is a bit sad of me but I was imagining what a good thing if ds went to uni because I would be able to send some of the excess towels and sheets with him
and not have to throw them away. I don't iron things though which allows the laundry to move faster through the system
I tend to wash things, hang them over the bannister and hope someone puts them on before I have to put them away...
I think letters can be kept, they don't really take up much space compared to all the other things we fill our lives with (magazines, excess crockery, clothes, ornaments) I think letters are historical documents not clutter.
I'm not sure what to advise on the house sale front - would it be worth putting some things into temporary storage so you can declutter at your leisure or assess whether you want to keep them when you have moved house? Might make it easier to organise and clean the house for the sale. I know it is an expensive short term solution but it is difficult without knowing what your new house/flat is going to be like to bring oneself to dispose of useful furniture things in advance. I remember putting stuff into storage, bringing it out, putting in the loft o fnew house, and then throwing it all out ten years later, really made me think what a wasted opportunity it was to keep it all so long. things like fabric for curtains and old clothes, old duvets, sleeping bags excess to requirements. Never found any of it when I needed it, as there was too much in the loft, and then I never really wanted to use the fabric as it was the wrong kind (10 years on) So so glad I got rid of it I haven't missed ANY of it 2 years later.