Leeny, I have bf both my children - DS until 2yrs, and now still feeding DD who is 2.5yrs.
With DS I went back to work 2 days a week and he just had food and water when he was with his childminder, had milk morning and evening (and through the night). In fact he carried on with just one feed first thing in the morning between 18m and 2yrs. He did seem to lose interest in day feeds after I went back to work, and I didn't realise that I could offer.
With DD I didn't work at all, and she has definitely had more feeds for longer (still has some day feeds now). And at 13 months bm was definitely still a big part of her diet, as well as being comforting for her. I felt more relaxed about offering her milk, rather than feeling that I should be making her stop. I know more people in RL who have fed for longer this time round, which does help with confidence.
Try not to see expressing as an indication of your milk supply. I only really expressed when my two were under 6months (and that was rarely), and found that as they got older I got less out, but they were obviously still getting milk!
DD occasionally has cows milk as a drink, but I don't see it as something that I should encourage her to drink lots of. I have never used bm in cooking (even when weaning) as I tend to cook one meal for the whole family.