Mix softened butter, maple syrup and chopped thyme into a paste.
Place chicken into a roasting pan and stuff cavity with lemon and all but the 4 sprigs of thyme. Loosen the skin on the chicken breast and thighs and spread half of the butter mixture under the skin. Rub the remainder of the butter mixture on top of chicken that has been seasoned with salt and pepper.
Roast the chicken until a thermometer, inserted into the thickest part of the thigh, registers 165 degrees F. (about 1.5 hours). Remove chicken, cover loosely with foil and let it rest for 10-15 minutes. Carve chicken and garnish with the remaining thyme sprigs.