It should not be anymore difficult. Ur milk will replenish as it gets low. You can also eat foods & teas that help build up ur milk supply.
I am breastfeeding my 8th baby currently but I have never breastfed twins so I don't know about that or how it's done. Nursing one is demanding enough. LOL! You might go to the breastfeeding community and ask there. I am a CL there too but don't know if or how this might be different from nursing a singleton. Good luck though! How exciting!!!
My sister in law had twins and is still breastfeeding them at 19 months. It might not be easy but can be done! Good luck!