Will Pepe and wif survive 1 year? I think they are too big already to disappear.
No one can guarantee this. Even the chance of these coins to survive is likely high, it is not impossible if they will disappear someday. Don't forget that these are meme coins! If the hype is over, the demand will drop constantly. Moreover, we have too many meme coins now, the competition among meme coins may bring bad impacts to some meme coins. Even if PEPE or WIF is top meme coins, the hype is still possible to be over.
Keep in mind I just wanna open a speculative position and it's just a small part of my overall portfolio
If it will be a small part of your portfolio, I think it is no problem. However, you need to make sure choosing meme coins that look having good news in the future. Take a research about the plans or roadmap made by the teams!
Most coins that have a market cap above $1,000,000,000 will be a good investment if you HODL for one year. We are 12-18 months away from a blow off top in this crypto cycle so any reputable token or coin should do really well in this bull season.
Do you mean each coin with market cap $1,000,000,000+ are safe for investment? I don't think so. If it is a meme coin, I personally assume it is still very risky. Unless it is for fundamental coins that have big community, I don't determine good or bad coins based on the market caps. By the way, we only can guess the peak of this bullrun season. It can be less than 12 months or more than 12 months from now. However, just remember that no every coin may hit a new ATH even if it is in the peak time of the bullrun season.