1) We don't yet have enough renewables for this to be an issue. Even with the most optimistic possible build-out timelines for additional renewable generation, we will not do so for another decade or two. That's why it's important to change building practices for new-build and refurbs now since the incremental cost for additional insulation is much less than the cost of retro-fitting.
2) "base load" isn't the best term here. Base load refers to the load that makes up the bottom of the load curve, basically a straight horizontal line right under the trough in demand. Some of base load actually is flexible load - for instance refrigeration equipment that runs overnight can be timeshifted by an hour easily (although in that case it is rarely done because power prices are cheap at that time). The problem for renewables is not base load but non-flexible / non-dispatchable load that must go on when requested such as lights or televisions.
2) "base load" isn't the best term here. Base load refers to the load that makes up the bottom of the load curve, basically a straight horizontal line right under the trough in demand. Some of base load actually is flexible load - for instance refrigeration equipment that runs overnight can be timeshifted by an hour easily (although in that case it is rarely done because power prices are cheap at that time). The problem for renewables is not base load but non-flexible / non-dispatchable load that must go on when requested such as lights or televisions.