For me, cold feet are the bane of winter paddling. Everything else on me stays warm: warm hands, warm head, warm ears and warm rest of me but not my feet. My feet are always freezing. To address this I've spent a lot of time (and money) trying to keep my feet warm while winter paddling because I find that if my feet are painfully cold I can't concentrate on anything else and it completely ruins the day.
Thankfully, since the days of my apprenticeship of misery, when I wore old trainers and woolly socks and cried with pain a lot, technology and equipment have moved on and although I wouldn't describe my toes as toasty at this time of year they're certainly a lot warmer than they used to be.
My current footwear solutions for combatting cold toes throughout the year are as follows:
Mid to late summer when the water's nice and warm - watersports shoes such as the NRS Vibe - https://www.south-coast-canoes.co.uk/nrs-vibe-mens.html - possibly paired with thin neoprene socks like the Palm Index - https://www.south-coast-canoes.co.uk/palm-index-neoprene-socks.html - work fine. I usually wear the socks anyway, despite the fashion faux-pas, because they prevent blisters and stop grit from getting in and sanding my feet raw.
Winter - currently from about October to mid-September :-) - If I think I'm likely to swim I wear a dry suit, if not, dry salopettes, both with dry socks though and thick woolly socks underneath. This is probably the warmest I ever manage to get and the relief at being able to stand thigh deep in freezing water and actively not feel wet and cold is still a marvel to me. I usually wear sturdy shoes or boots like the Palm Gradients https://www.south-coast-canoes.co.uk/palm-gradient-boot.html because with their rounded heel they're comfy to wear in a boat, laced footwear is easier to fit drysuit socks into and the Palm gradients have a removable insole to allow more space for thicker socks. To preserve the life of my drysuit when launching from sandy or gritty beaches I wear thin neoprene socks OVER the drysuit socks and thin but warm fleece liner sock, palm Tsangpos - https://www.south-coast-canoes.co.uk/palm-tsangpo-sock.html