Toe covers aren't enough if the temps are too cold for your feet. Try some good booties. They can be pricey but much cheaper than winter boots. After a miserable ride when he got caught in the rain on a cold day last week, my husband got some Mavic booties that even have some sort of pocket for warmers. I have some lightweight neoprene ones that are much warmer than toe covers. Still, my feet got too cold in the 30s and low 40s even with booties last year. Doesn't help that the cold tends to slow you down. I found winter road boots steeply discounted and splurged. I think warm shoes are the best solution. It's just too hard to ride with cold hands and/or feet.