This was almost half way through my expeditions and I was starting to feel confident in Winter mountaineering and my ability to look after myself. The conditions weren't so concerning for me as I had skied to the North Pole by this point and it could not be anything like as cold as that.
Denali is a fairly simple mountain. There is little technical challenge on the main route and whilst storms can be bad when they blow in I don't get the impression that they are too much to worry about. The problem can be that the summit is pretty exposed and storms can last for a few days there meaning that you need to have plenty of spare days in case of bad weather.
The main challenge on the mountain is the amount of stuff (equipment, food gear, clothes) that you need to drag up and down and so a fair degree of physical strength is needed - or a partner / tent mate happy to share your load!
If you are going in a guided group, you need to use one of the 6 (or so) concessionaire companies that have been licensed by Denali national park. I am not sure how much difference there is between them. All groups use the same route, although there are other non-guided routes for more advanced climbers wanting a proper challenge.
The main decision is time of year. Spring can be pretty cold but Summer has problems with the snow on the lower slopes melting and crevasses opening up. Since it easy to deal with the cold by wearing an extra layer, but not much you can do about the snow melting, I would tend towards going earlier on in the season.
The route is a fairly simple one up the mountain. There are guide sticks every now and then and only a few steepish sections. From ABC, there is a steep slope and an exposed ridge up to High Camp and a few slopes and ridges from HC to the summit. The views are generally stunning whic helps!
Accounts and photos of completing the Explorers Grand Slam - 2 Poles and 7 Summits. By Sebastian Merriman. Aconcagua, Ama Dablam, Carstenz Pyramid, Denali, McKinley, Elbrus, Everest, Kosciusko, Kilimanjaro, North Pole, Arctic, South Pole, Antarctic, Antarctica, Vinson, vertigo, climbing, mountaineering, skiing to the pole, skiing to the poles, seb2poles7summits, seb27, Seb Merriman, seb2poles, mountains, poles