A guide to how climate change will affect different countries
There's a fair bit of unknowns for what you're asking, 300 years and specifics.   For one, climate change modeling is based off CO2 levels and CO2 levels long term are difficult to predict.   That's why they run hundreds of models, each with different circumstances.  Nobody can make an accurate assessment of mankind's CO2 output will be 50 or 100 years so the further out you go the greater the unknowns.  Targets are being set for 2050, but whether they will be reached is a big unknown and I've never seen anything that goes for 300 years.  Most of the models run till 2100.   

Some Unknowns: 


Will CO2 PPM peak at 500 or 600 or higher?   Will it fall below 400
in 100 years?
Will the oceans continue to absorb CO2 or will they warm to the point
where they stop.
Will the North Atlantic current stop or weaken?   That would have an 
enormous effect on European climate.
Will large chunks of ice break off or will the ice sheets remain
mostly intact?


These are impossible things to predict with any accuracy and they significantly effect the outcomes you've asked for.

Smaller effects, such as whether the Sun will enter an extended solar minimum or whether we have a big volcanic eruption like the one in 1815 (which would slow things down for 5-10 years, but wouldn't have a significant long term effect).   Other questions are whether parts of the Earth can be greened, artificially, which might not measurably slow down the warming but it could ease the effects of drought in some areas.  

Bottom line is that "basic" predictions might be just as good as detailed because of all the unknowns.   A few aspects are pretty straight forward, like knowing the effect of 1 foot of sea level rise, but predicting how fast the oceans will rise 1 foot is very difficult.   The effects of ocean acidity and some weather driven species migration is somewhat predictable too.   Predicting where droughts are more likely to happen can be done as well, but as I said above, might be preventable with strong irrigation efforts.  

Rough predictions aren't hard to find, but for the 21st century only.  Anything further out than that is probably lots of guesswork and not carefully modeled.    Basic and this century is probably as good as this field of study gets.  

Articles here and here.  I imagine those are both based on the 5th assessment report.   

footnote:  If you read assessment reports online, keep in mind the labeling system - 5th; AR5,  4th; AR4, 3rd; TAR, 2nd; SAR, first; FAR.  Given how fast this field tends to update, I'd mostly just read IPCC reports labeled AR5, perhaps AR4.   Anything before then is quite dated by now.