I'm not a financial expert here, so some of the things you hit on in your reply I am not familiar with. I've never used GICs. RRSPs however can be invested, or sit in cash non-invested. Its the same account type either way.
Some, like BMO Investorline, will charge for it to sit in cash (Investorline charges you $100/month) - BMO Smartfolio won't let you put things in cash, they say they aren't setup for that.
I ended up moving my RRSP to an RRSP with my credit union. Its getting moved to an RRSP but it will sit in cash hold, uninvested, until such time as I am ready to put it back into the market. I did this before the 2020 dip as well. You can avoid the bubble popping this way. It doesn't need to stay on the market.