If 98% of your portfoli is bitcoins, 2% for altcoins, it's posisble to store altcoins in many wallets like Metamask, Myetherwallet, and more. They are not safe like hardware wallets but if you don't want to store them in a same hardware wallet of bitcoins, don't want to store them in exchange accounts, it's your only method.
I probably exaggarated a bit (percentage is probably 95% 
), but I simply don't trust those hot wallets with anything more than $100-200$. If your fund is big, I don't see how you can not afford to spend money for purchasing a second hardware wallet that is used only for altcoin storage.
Hardware wallets are so cheap nowadays that I don't think anyone could have issues buying 2nd one, but its simply pain in the ass to have to deal with that one as well. At least it is for me (maybe I am just lazy).