Now implementing this strategy is the most ok, because the current BTC prices are very low and can fall deep, so buy them now do not miss the opportunity.
buying btc is good but selling alts this time is not that good because the price is also low you can sell it but with a low value so it is better to hold it and buy bitcoin form your fiat but if you got nothing you can sell your alts because the chance you can earn with a good value is on the side of bitcoin.
Indeed, current situation is not good for selling our altcoin because most altcoin in market drop the price more than 70% from highest price. I think i am better waiting price increasing and selling my altcoin to bitcoin. But sometimes investing on altcoin and hold it as long term investment is profitable because movement on altcoin more attractive than bitcoin
With the market price that is dropping at its 70% from its highest value, all you need is patience because most of the people who sell their coins at its lowest price just lose a huge amount of their capital since the market will still go back at its previous prices but it will take a long time.