Unfortunately Dee and I do not have an indoor at our barn,(P.S. we live in NY). I want to keep him in work as long as the footing is decent. Any tips on staying warm... great products you've tried, (particularly for hands and feet)?
I have an indoor, but it's not heated. Temperatures here can get to -35, and are often -20 for periods in the late fall and mid-winter. When it's that cold we don't ride, but we do regularly ride to -10. I have hay salt in my footing so that it doesn't freeze until about -25, and of course it thaws much faster if it does freeze, so that doesn't usually keep us from riding.
We ride in Kerrits Sit Tight 'n' Warm breeches (full seat), Mountain Horse Ice High Rider tall boots, undershirts/turtlenecks, a thick fleece vest, and a padded jacket overtop. We wear wool socks (you can get great deals on e-Bay on those), and Greenhawk's microfibre winter riding gloves, which are not too bulky but are warm enough. The jacket stays on for the walk warmup, and comes off once we start trot work (or we overheat)., and it goes back on when we start to cool down. On cold days (usually -5 or more) the horses wear quarter sheets throughout their work.
We keep our horses under lights in the winter, so they don't grow winter coats, and they stay much more comfortable and cool in their work that way. We use Greenhawk Shedrow Gold turnout blankets, which keep them warm to -30 without underblankets, and they stay dry and warm regardless of the weather. They are turned out in 5 acre pastures in small groups, so they are very hard on blankets, but we've found that the Bucas and Shedrow Gold blankets stand up to everything they do, and keep them warm and dry. You can even put these blankets on damp horses and they will dry underneath and the blanket will stay dry and warm as well.
I have radiant heat patio heaters installed in my tacking/grooming area, and we all really like those (as does our farrier). At really cold clinics, when I want to use my leather boots instead of the Mountain Horse boots I use "Hot Shots", which are little activatable packets which stick on the bottoms of your socks. They will keep your feet warm for 6 hours, and you can get hand warmer versions too for pockets and in glvoes/mittens. They do add up though, so we use them only for clinics/teaching.
I wear most of the same things as above to fight the cold (fleece vest, wool socks, turtle neck etc), except I wear the Mountain Horse Rimfrost tall boots for my day to day riding. They are a bulkier boot so it takes some adjusting to them to easily pick up stirrups, and the shaft is a bit thick and stiff... but they are toasty warm. I wear Ariat Bromont tall boots for lessons and clinics. They are warmer than my regular tall boots, but I do sometimes add 'Hot Shots' as well. I like the look of the Bromonts (quite similar to regular field boots) and they also have a similar foot shape and shaft to my regular tall boots, so I can feel the horse and stirrups better than I can in the Rimfrost boots. I wear both types, but I prefer alpaca socks to sheep wool ones as I find them less itchy, and I have a couple of pairs that are thin enough for my field boots and yet are still quite warm.
I do also tend to wear long underwear, especially if I have a lot to do around the barn before/after riding, or I am just hacking and not working up a sweat. I love Under Armour stuff, but there are other brands of technical fibre long underwear, and silk is also awesome. I sometimes get wussy and wear the Greenhawk winter 'chaps' (really overbreeches) for hacks. I also like their winter helmet cover if there is any wind. Riding mittens are warmer than gloves (SSG and Mountain Horse both make nice ones), and they have a split for the little finger to allow the reins to be held in a normal fashion. I do stick with gloves for lessons and clinics... I have SSG winter gloves, but usually I wear the Greenhawk microfibre winter riding gloves because they are cheap enough to have a few pairs so that they can dry out between rides if they get wet. I also occasionally wear glove liners.
... and one great way to add warmth to a winter ride is to ride bareback. :)