We go to South Fork every summer pulling a 5er. Similar to above except from 287 we take I-40 to Vega (west of Amarillo) and take US 385 north toward Dalhart. I think a little easier as you do not have to get thru Amarillo except on the interstate and you miss going thru Dumas.
Two passes. Ration Pass is not bad. A little tug the last mile or so near the top.
La Veta Pass west of Walsenburg is a little harder but really not too bad.
If you prefer to skip the passes you can stay on I-40 until you can cut up to Santa Fe and on up to Alamosa. A little farther but not much.