Good news, Alison. Cats without teeth cope well. Pad had to have a load of his out when he was around the same age as Parki. The gums heal and harden, and they can gum away at food quite easily in a relatively short while. Paddy used to eat wet and nibbles without difficulty.
I remember when Paddy had his dental. We went to collect him and he was soooo wobbly when we let him out, but he was determinedly making a beeline for the back door. I was reluctant to let him out, but he wailed so pitifully, I did. He wobbled out onto the patio, and flopped through the hole in the gate onto the field with me in pursuit. He then collapsed on the grass, and just lay there, taking in the greenery and the air on his whiskers. He had a little sickie, and then he looked at me as if to say "S'okay - we can goes back indersides now...."