I just got done with my 4 year performance review call with my boss (the CTO) where the review was extremely positive and my boss was fishing pretty hard for me to name a number on my target salary. They could not give raises this review period due to company performance, but are hoping to give them early next year.
At the end of the review, my boss asked what number would make me happy as "me leaving would be pretty hard on the company and also him personally (he's mentored me quite a bit) and if I'm considering looking to let him know".
I do have a number that would make me happy, but that number is about 1.75-2x what I'm currently making (I believe I'm underpaid for my current responsibility). However, I've been strongly considering trying to move towards consulting + pursuing a product business next year (with him as a part-time client) and I worry that naming a 2x number would cause animosity if he was not able to meet it.
Besides the money, I enjoy the work and my boss quite a bit, though also feel like I should get experience with different companies and industries (where I think consulting might be useful).
Do I have much to lose naming a 2x number?
Edit:
To add a little more nuance to the situation, the major perk that has kept me in this job so far is that he's allowed me to work remotely from Asia for the last couple of years and is very flexible with schedule.
The reason for the 2x number is due to the fact that my responsibility has increased significantly in the last ~8-9 months by moving into an architect role and overseeing the technical design of the majority of the company's projects. Before this transition, I feel like I was underpaid by ~20-30% compared to similar jobs in the region the business is located in (but the location flexibility has kept me), but after the dramatic increase in responsibility I see similar jobs in the region the business is located in going for 2x my current salary. (Note that I originally started working in the office in this region before moving to Asia).
I greatly appreciate all of the answers here and it has helped me take a step back and try to view the situation from multiple angles!