I wouldn't exactly sell bitcoin right now, but if I imagine, I would split the budget 50/50, leave half in USDT, and invest the other half in the top alts.
For those who buy bitcoin above the price of $7000 will certainly keep their bitcoin as long as possible but for traders who are looking for profits by buying bitcoin under $7000 of course this is the right time to sell it, 
I think by choosing usdt as an investment asset it looks like you are looking for safe for your money now, because we know usdt is one of the altcoins that prices are quite stable at the moment.