This is very opinion based and also a future reader may view this answer and the question in the light of their current market conditions. Despite all that you there are some principles that remain timeless.
The first is your core question boils down to one of risk. Do you accept volatility risk of being heavily invested in equities for a short term (1-3 years)? Or do you accept a deflationary risk? The deflationary risk is real in that housing prices could increase much faster than safe and secure investments or even equities.
The thing I like least about the hints you provide to the make up of your portfolio is the amount of your net worth is tied up in a single company stock. Not only is your income tied to this employer, but also 30% of your portfolio. I would be shooting for the 5-10% range, and error on the side of the lower amount as you will continue to vest more options.
The second thing I dislike about your portfolio is the individual shares that you own. It would be far safer to invest in the broader market.
If it was me, I would do the following for money earmarked to buy a house:
30-60% in a high interest savings account. This will earn you about 1.5%-2%
60-35% in a diversified portfolio of stocks. In the US, something like an S&P500 fund.
5-10% in my company stock options only if I really like the outlook of the company. If not then zero.
I like this plan, because if you lose your job, the company options become worthless, and the stocks tank to 40% of their current value you will still have a healthy down payment for the home. Provided you can secure subsequent employment, you should have no problem obtaining a mortgage.
If things continue to grow, well then you also get growth on those fund so invested.
I would also use a different allocation for money that is not earmarked for purchasing a home.
Also I would tend to use REITs to provide a bridge between the safe savings and equities, but you said that you expect real estate prices to drop, so that probably isn't a good idea.