I had to cancel 3 premium plus tickets to Asia due to family plans, which now means we have over 400K+ united points now "stuck" in United. My husband flies United a lot but for work so we won't need to use his flights these. I also am restrained with the usual school schedule as my kids are middle school + and can't skip out during school days anymore.

So looking for some good recommendations and open jaw route options for us to book for a family of 4 for next spring break in April or early June for next Summer on United. Maybe some good route that would normally have more saver fares?

Some cities/countries of interest, with hopefully 1 or more stopover countries convenient to visit as an open jaw/stop over.

Asia: Japan/South Korea/Taiwan/Singapore
Europe: London, Ireland, Iceland, France, Germany, Belgium, Denmark, Norway, Portugal, Greek Island

Any suggestions would be welcome. I'm guessing I will have to stick with economy flights for family of 4. We do have maybe another 200K chase points that can be transferred around if needed.

TIA!
Update, closest airport is SFO.