Diag w/ BCC, growing since 2007, 1 cm diameter. May have to wait months for any treatment - How big could this be? (photo)

Mohs is the best procedure to treat an incompletely excised basal cell cancer on the face. Treatment should not be delayed for six months. 

I would ask to have the slides re-reviewed by another lab (dermatopathology preferred) and get a subtype.  If it is nodular BCC and if it would take over 6 months to get Mohssurgery  then I would discuss with your surgeon if (s)he would choose curette the lesion to get a pretty good size estimate and then excise with maybe 3mm margins. In that location it should heal well. However, if the subtype is more concerning (infiltrative, sclerodermiform ...) I would press hard to get Mohs ASAP. Good luck.

It would be helpful to know if this is a nodular BCC, but truly, if you have to wait months for the procedure, I'm not sure knowing that is going to be excessively helpful or not. BCCs grow like trees. Often the top of the tree is small, but the roots can grow far and wide. If you've had this cancer since 2007, the likelihood of a bigger root system is probable. Within 6 months the site most likely won't have grown that much, but it would have been more ideal had you been seen in the last 7 years! If you can ask for a closer appointment it would be better for you, but you can wait 6 months if you have to. "This answer has been solicited without seeing this patient and cannot
be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."