Hard cheeks after midface lift?

At 2 weeks there is likely swelling present and I would followup with your surgeon...  Facial fillers may address other areas but it is important to understand the longevity of the filler

Swelling and contour irregularities may be present for weeks after a facelift, depending on the technique.  As the swelling resolves you will feel less tightness and, if your facelift was done well, will begin to look more natural.  

This is difficult to answer without an in-person evaluation. I recommend following up with your surgeon about your concerns. It is still too soon for your final results. You may still have some swelling, which will slowly resolve over the next several weeks. I hope this helps. 

Kristin.  I appreciate your concern but it is too early to think about any fillers because there is most certainly swelling still present.  The firmness should also settle down with time. Try to stay patient and allow yourself to heal and follow up with your plastic surgeon. Best of luck.

It seems that your recovery after surgery is going okay. After two days, the swelling is at a maximum and then starts getting better. 
To answer your one question, yes usually it is not uncommon for things to be swollen after a facelift. Usually it's worse the first week but gets better every week. I know it's hard to be patient after surgery.
If it does not settle, you can undergo corrective surgery with additional surgery.  I would recommend that you see a board-certified plastic surgeon in your area that is a member of both ASPS & ASAPS and performs a lot of facelifts if you want a second opinion and of course, make sure you follow up with your own surgeon and talk about this if you have concerns that linger. 
I hope this helps and wish you all the best in your surgery and event. If it does, please take a moment to up vote this answer on the “respond” button on the top right.  

Thank you for your question.Hardening of the cheeks can last anywhere between 6 and 8 weeks before it resolves from a mid facelift. Filler can definitely be a great addition after a mid facelift and I always recommend it to my patients,. Every surgeon is different. I will not inject any filler until 6 weeks post operatively, which is when most swelling has gone down.Be patient. Hope this helps!

Cheek firmness can last quite a bit of time after a midface lift. It can take several months for the swelling to subside.. Best of luck.