In my opinion, it is better not to liquidate your bitcoins. If you want to invest in altcoins you better use a small number of your bitcoins to buy some altcoins which have strong fundamentals. No one knows for sure if bitcoin has reached its peak, it could be that in the future the price of bitcoin will continue to increase. therefore it is better for you to save bitcoin
Liquidating or converting all of bitcoins into altcoins, that's not a wise thing to do. You're like throwing your money and do not have plans of getting them back.
A small part of your bitcoin to be sold for altcoins, I don't think it's also a good idea. It's better if you're going to have an allocated budget for it when you buy altcoins.