If ever bitcoin sending fee will be super high i think i will still use my bitcoin for transaction but it depends on how high the fee was . some sites , wallets , exchanges do have different transaction fees and some enables you to choose between slow , mid and high priority . i will only choose mid or low if high priority is too expensive .
But if all the options above are not possible i guess ill have to use another cheaper coin if available .
You can just use your Bitcoin for transactions over $100 and for less then $100 you use doge or eth or ltc or something. Many more places have now accepted altcoins and have a drop down menu to select them.
Coinpayments has had this for quite a while now. It also helps get more people involved and using altcoins. Giving use to more coins then just bitcoin is a great idea.