Hello and thank you for the question.
You may be surprised at how much you can do with a good plan. Likely you will be able to come up with a plan that works with keeping 3 bedrooms. Sometimes by moving closets, moving a door and adjusting a wall or two you can reconfigure a space to accomodate a 3/2 when you may have thought that was not an option.
Some of these ideas may help:
Look at floor plans on line with the same amount of sq ft in the footprint for ideas on room placement.
Think outside the box, maybe you can do an additional full bath without the tub...a shower can be the space savings you need- especially if you insert a corner shower.
You might choose floor to ceiling corner cabinetry to use space more efficiently with versatile design style.
A pedital sink, wall mounted sink or petite vanity are all choices that are available in high-style, space savers.
There are even compact toilets (still standard size, but with space saving design).
I hope you keep those 3 bdrooms! You'll lose value more by losing a bedroom than you'll gain by additing a bath in its place. But having both is best. Keep in mind, even a 1/2 bath (powder room) off a kitchen or laundry room would help increase value....depending on layout, you might have more options than you've considered.
I wish you well!
June Lizotte, Principal Broker
June Lizotte Real Estate
Providing REAL Service