Walt you are getting ahead of yourself. Seems like you are worrying about a procedure that may not even have to be done. But , should you need a total glossectomy plus or minus whatever ( depends on where the tumour extends too, or not ), you will be ok.
If you only have a total glossectomy you will breathe in the normal way same as everybody else.
Kris eats, well swallows liquids.
He has major dental issues post rads and trismus, but that is improving.
There are good apps you can download onto an IPad that will speak what you type. ( Speakit app ).This is a tad slow but is ok. You should be able to talk with the help of a speech therapist . Try holding your tongue still and talking. It is quite intelligible..
Honestly try not to worry about things that may not happen.
If they do, I can honestly say life is still great and well worth living.
Thinking of you,
Tammy

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!